Calculation of force by subtracting the same denominator
Publish: 2021-05-09 17:29:07
1. The calculation method of fraction addition and subtraction:
1) if the denominator is the same, only the numerator is added and subtracted, and the denominator remains unchanged
2) if the denominator is not the same, first divide it into the same denominator, then add and subtract< I. definition: integral a divided by integral B can be expressed in the form of. If the Division B contains letters, it is called a fraction
note: a ÷ B= =A × = A × B-1= A• B-1 Sometimes it is written as a negative index, i.e. a & 8226; Composition: in the fraction, a is called the numerator of the fraction and B is called the denominator of the fraction
III. meaning: for any fraction, the denominator cannot be 0, otherwise the fraction is meaningless
IV. condition of fraction value 0: if the denominator is not equal to 0 and the numerator is equal to 0, then the fraction value is 0
note: the concept of fraction includes three aspects: 1) fraction is the quotient of the division of two integers, in which the numerator is the divisive, the denominator is the divisive, and the fractional line acts as a division sign; ② The denominator of a fraction must contain letters, while the numerator may or may not contain letters, which is an important basis for distinguishing integers; ③ In any case, the denominator value of the fraction can not be 0, otherwise the fraction is meaningless. Here, the denominator refers to the division. It's not just about one letter in the denominator. That is to say, the condition that the denominator of a fraction is not zero is implied in the fraction and need not be specified< Basic properties of fraction: the numerator and denominator of a fraction are multiplied or divided by the same integral that is not zero, and the value of the fraction remains unchanged< Rection steps: (1) if both the numerator and denominator of a fraction are monomials or the proct of several factors, rece their common factors. (2) both the numerator and denominator of a fraction are polynomials, and separate the numerator and denominator into factors, Then, the common factor is reced.
note: the extraction method of the common factor: the coefficient takes the greatest common divisor of the numerator and denominator coefficient, the letter takes the common letter of the numerator and denominator, and the index takes the minimum index of the common letter, which is their common factor.
VIII. The simplest fraction: when the numerator and denominator of a fraction have no common factor, this fraction is called the simplest fraction, Generally, a fraction is reced to the simplest fraction.
IX. general division: the general division of a fraction is to change several fractions with different denominators into fractions with the same denominator, which are equal to the value of the original fraction.
X. the general division of a fraction is to find the simplest common denominator of the denominator of all fractions, and then change the denominator of all fractions into the simplest common denominator, The corresponding molecules are expanded.
note: the determination method of the simplest common denominator: the coefficient is the least common multiple of each factor coefficient, The proct of the highest power of the same letter and the power of a single letter.
note: (1) the basis of rection and general division are the basic properties of fractions. (2) the rection and general division of fractions are reciprocal operations.
section 3 four operations of fractions
Xi. The addition and subtraction rule of fractions with the same denominator: the denominator remains unchanged, the molecules are added and subtracted.
XII, According to the law of addition and subtraction of fractions with the same denominator.
XIII, The proct of the denominator is the denominator.
XIV. Division rule of fraction: change the division formula into its reciprocal, and then multiply it with the divided formula.
section 4 fraction equation
XV. Meaning of fraction equation: the equation with unknown number in the denominator is called fraction equation.
XVI. Solution of fraction equation: ① remove the denominator (multiply both sides of the equation by the simplest common denominator at the same time, and the fraction equation becomes integral equation); ② According to the steps of solving integral equation, the value of unknowns is obtained; ③ The root test (the root test must be performed after the value of the unknowns is obtained, because in the process of transforming the fractional equation into an integral equation, the range of the unknowns is expanded, and the root increase may occur)
1) if the denominator is the same, only the numerator is added and subtracted, and the denominator remains unchanged
2) if the denominator is not the same, first divide it into the same denominator, then add and subtract< I. definition: integral a divided by integral B can be expressed in the form of. If the Division B contains letters, it is called a fraction
note: a ÷ B= =A × = A × B-1= A• B-1 Sometimes it is written as a negative index, i.e. a & 8226; Composition: in the fraction, a is called the numerator of the fraction and B is called the denominator of the fraction
III. meaning: for any fraction, the denominator cannot be 0, otherwise the fraction is meaningless
IV. condition of fraction value 0: if the denominator is not equal to 0 and the numerator is equal to 0, then the fraction value is 0
note: the concept of fraction includes three aspects: 1) fraction is the quotient of the division of two integers, in which the numerator is the divisive, the denominator is the divisive, and the fractional line acts as a division sign; ② The denominator of a fraction must contain letters, while the numerator may or may not contain letters, which is an important basis for distinguishing integers; ③ In any case, the denominator value of the fraction can not be 0, otherwise the fraction is meaningless. Here, the denominator refers to the division. It's not just about one letter in the denominator. That is to say, the condition that the denominator of a fraction is not zero is implied in the fraction and need not be specified< Basic properties of fraction: the numerator and denominator of a fraction are multiplied or divided by the same integral that is not zero, and the value of the fraction remains unchanged< Rection steps: (1) if both the numerator and denominator of a fraction are monomials or the proct of several factors, rece their common factors. (2) both the numerator and denominator of a fraction are polynomials, and separate the numerator and denominator into factors, Then, the common factor is reced.
note: the extraction method of the common factor: the coefficient takes the greatest common divisor of the numerator and denominator coefficient, the letter takes the common letter of the numerator and denominator, and the index takes the minimum index of the common letter, which is their common factor.
VIII. The simplest fraction: when the numerator and denominator of a fraction have no common factor, this fraction is called the simplest fraction, Generally, a fraction is reced to the simplest fraction.
IX. general division: the general division of a fraction is to change several fractions with different denominators into fractions with the same denominator, which are equal to the value of the original fraction.
X. the general division of a fraction is to find the simplest common denominator of the denominator of all fractions, and then change the denominator of all fractions into the simplest common denominator, The corresponding molecules are expanded.
note: the determination method of the simplest common denominator: the coefficient is the least common multiple of each factor coefficient, The proct of the highest power of the same letter and the power of a single letter.
note: (1) the basis of rection and general division are the basic properties of fractions. (2) the rection and general division of fractions are reciprocal operations.
section 3 four operations of fractions
Xi. The addition and subtraction rule of fractions with the same denominator: the denominator remains unchanged, the molecules are added and subtracted.
XII, According to the law of addition and subtraction of fractions with the same denominator.
XIII, The proct of the denominator is the denominator.
XIV. Division rule of fraction: change the division formula into its reciprocal, and then multiply it with the divided formula.
section 4 fraction equation
XV. Meaning of fraction equation: the equation with unknown number in the denominator is called fraction equation.
XVI. Solution of fraction equation: ① remove the denominator (multiply both sides of the equation by the simplest common denominator at the same time, and the fraction equation becomes integral equation); ② According to the steps of solving integral equation, the value of unknowns is obtained; ③ The root test (the root test must be performed after the value of the unknowns is obtained, because in the process of transforming the fractional equation into an integral equation, the range of the unknowns is expanded, and the root increase may occur)
2.
Add fractions with the same denominator
1, add fractions with the same denominator, keep the denominator unchanged, add the molecules, and finally turn into the simplest fraction
example 1: 2 / 9 + 5 / 9 = 2 + 5 / 9 = 7 / 9
example 2: 1 / 8 + 3 / 8 = 1 + 3 / 8 = 4 / 8 = 1 / 2
Add fractions with different denominators
1, add fractions with different denominators, first divide, then add fractions with the same denominator to calculate, and finally rece to the simplest fraction
case 1: 3 / 4 + 5 / 7 = 21 / 28 + 20 / 28 = 21 + 20 / 28 = 41 / 28
case 2: 5 / 24 + 1 / 8 = 5 / 24 + 3 / 24 = 5 + 3 / 24 = 8 / 24 = 1 / 3
score addition and subtraction
fraction subtraction
same denominator fraction subtraction
1, same denominator fraction subtraction, denominator unchanged, molecular subtraction, finally to the simplest fraction
Example 1: 5 / 9-1 / 9 = 5-1 / 9 (get the number to the simplest fraction)= 4 / 9
example 2: 3 / 4-1 / 4 = 3-1 / 4 = 2 / 4 (get the number to the simplest fraction) = 1 / 2
different denominator fraction subtraction
1, different denominator fraction subtraction, first pass the score, and then according to the same denominator fraction subtraction method to calculate, finally to the simplest fraction
example 1: 7 / 8-1 / 4 = 7 / 8-2 / 8 = 7-2 / 8 = 5 / 8
example 2: 8 / 15-1 / 5 = 8 / 15-3 / 15 = 8-3 / 15 = 5 / 15 = 1 / 3
{rrrrrrr}
extended data
different denominator fraction addition and subtraction method, first general score, then according to the same denominator fraction addition and subtraction method, denominator unchanged, numerator addition and subtraction, finally approximate score
3. The calculation method of fraction addition and subtraction:
1) if the denominator is the same, only the numerator is added and subtracted, and the denominator remains unchanged
2) if the denominator is not the same, first divide it into the same denominator, then add and subtract<
fraction
section 1
basic concepts of fraction
I. definition: integral a divided by integral B can be expressed as the form of
. If there are letters in Division B, then
is called fraction
note: a ÷ B=
=A ×< br />=A × B-1=
A• B-1 Sometimes
is written as a negative index, i.e. a & 8226; B-1 is different in form but not in essence.
II. Composition: in the fraction
A is called the numerator of the fraction and B is called the denominator of the fraction
III. meaning: for any fraction, the denominator cannot be 0, otherwise the fraction is meaningless
IV. condition of fraction value 0: if the denominator is not equal to 0 and the numerator is equal to 0, then the fraction value is 0
note: the concept of fraction includes three aspects: 1) fraction is the quotient of the division of two integers, in which the numerator is the divisive, the denominator is the divisive, and the fractional line acts as a division sign; ② The denominator of a fraction must contain letters, while the numerator may or may not contain letters, which is an important basis for distinguishing integers; ③ In any case, the denominator value of the fraction can not be 0, otherwise the fraction is meaningless. Here, the denominator refers to the division. It's not just about one letter in the denominator. That is to say, the condition that the denominator of a fraction is not zero is implied in the fraction and need not be specified< Section 2 basic properties and variant applications of fraction< Rection steps: (1) if both the numerator and denominator of a fraction are monomials or the proct of several factors, rece their common factors. (2) both the numerator and denominator of a fraction are polynomials, and separate the numerator and denominator into factors, Then rece the common factor.
note: the extraction method of the common factor: the coefficient takes the greatest common divisor of the numerator and denominator coefficient, the letter takes the common letter of the numerator and denominator, and the index takes the minimum index of the common letter, which is their common factor.
VIII. The simplest fraction: when the numerator and denominator of a fraction have no common factor, this fraction is called the simplest fraction, Generally, a fraction is reced to the simplest fraction.
IX. general division: the general division of a fraction is that several fractions with different denominators are reced to the same denominator with the same value as the original fraction.
X. the general division steps of a fraction are as follows: first, the simplest common denominator of the denominator of all fractions is obtained, and then the denominator of all fractions is changed to the simplest common denominator, Note: the method to determine the simplest common denominator is to take the least common multiple of each factor coefficient, The proct of the highest power of the same letter and the power of a single letter.
note: (1) the basis of rection and general division are the basic properties of fractions. (2) the rection and general division of fractions are reciprocal operations.
section 3
four operations of fractions
Xi, The multiplication rule of fractions: use the proct of molecules as molecules, The proct of the denominator is the denominator.
XIV. Division rule of fraction: change the division formula into its reciprocal and multiply it with the divided formula.
section 4
fraction equation
XV. Meaning of fraction equation: the equation with unknown number in the denominator is called fraction equation.
XVI. Solution of fraction equation: ① remove the denominator (multiply both sides of the equation by the simplest common denominator at the same time, and change the fraction equation into integral equation); ② According to the steps of solving integral equation, the value of unknowns is obtained; ③ The root test (the root test must be performed after the value of the unknowns is obtained, because in the process of transforming the fractional equation into an integral equation, the range of the unknowns is expanded, and the root increase may occur)
1) if the denominator is the same, only the numerator is added and subtracted, and the denominator remains unchanged
2) if the denominator is not the same, first divide it into the same denominator, then add and subtract<
fraction
section 1
basic concepts of fraction
I. definition: integral a divided by integral B can be expressed as the form of
. If there are letters in Division B, then
is called fraction
note: a ÷ B=
=A ×< br />=A × B-1=
A• B-1 Sometimes
is written as a negative index, i.e. a & 8226; B-1 is different in form but not in essence.
II. Composition: in the fraction
A is called the numerator of the fraction and B is called the denominator of the fraction
III. meaning: for any fraction, the denominator cannot be 0, otherwise the fraction is meaningless
IV. condition of fraction value 0: if the denominator is not equal to 0 and the numerator is equal to 0, then the fraction value is 0
note: the concept of fraction includes three aspects: 1) fraction is the quotient of the division of two integers, in which the numerator is the divisive, the denominator is the divisive, and the fractional line acts as a division sign; ② The denominator of a fraction must contain letters, while the numerator may or may not contain letters, which is an important basis for distinguishing integers; ③ In any case, the denominator value of the fraction can not be 0, otherwise the fraction is meaningless. Here, the denominator refers to the division. It's not just about one letter in the denominator. That is to say, the condition that the denominator of a fraction is not zero is implied in the fraction and need not be specified< Section 2 basic properties and variant applications of fraction< Rection steps: (1) if both the numerator and denominator of a fraction are monomials or the proct of several factors, rece their common factors. (2) both the numerator and denominator of a fraction are polynomials, and separate the numerator and denominator into factors, Then rece the common factor.
note: the extraction method of the common factor: the coefficient takes the greatest common divisor of the numerator and denominator coefficient, the letter takes the common letter of the numerator and denominator, and the index takes the minimum index of the common letter, which is their common factor.
VIII. The simplest fraction: when the numerator and denominator of a fraction have no common factor, this fraction is called the simplest fraction, Generally, a fraction is reced to the simplest fraction.
IX. general division: the general division of a fraction is that several fractions with different denominators are reced to the same denominator with the same value as the original fraction.
X. the general division steps of a fraction are as follows: first, the simplest common denominator of the denominator of all fractions is obtained, and then the denominator of all fractions is changed to the simplest common denominator, Note: the method to determine the simplest common denominator is to take the least common multiple of each factor coefficient, The proct of the highest power of the same letter and the power of a single letter.
note: (1) the basis of rection and general division are the basic properties of fractions. (2) the rection and general division of fractions are reciprocal operations.
section 3
four operations of fractions
Xi, The multiplication rule of fractions: use the proct of molecules as molecules, The proct of the denominator is the denominator.
XIV. Division rule of fraction: change the division formula into its reciprocal and multiply it with the divided formula.
section 4
fraction equation
XV. Meaning of fraction equation: the equation with unknown number in the denominator is called fraction equation.
XVI. Solution of fraction equation: ① remove the denominator (multiply both sides of the equation by the simplest common denominator at the same time, and change the fraction equation into integral equation); ② According to the steps of solving integral equation, the value of unknowns is obtained; ③ The root test (the root test must be performed after the value of the unknowns is obtained, because in the process of transforming the fractional equation into an integral equation, the range of the unknowns is expanded, and the root increase may occur)
4. Addition and subtraction of fractions with the same denominator: the denominator remains unchanged, and the numerator is added and subtracted.
that is:
when two fractions with the same denominator are added, the original denominator is used as the denominator of the sum, and the result of the addition of two molecules is used as the numerator of the sum.
for example, 2 / 5 + 1 / 5 = 3 / 5
when two fractions with the same denominator are subtracted, the original denominator is used as the denominator of the difference, The result of subtracting the subtracted molecule from the subtracted molecule is worse than that of the subtracted molecule.
for example, 5 / 7-3 / 7 = 2 / 7
that is:
when two fractions with the same denominator are added, the original denominator is used as the denominator of the sum, and the result of the addition of two molecules is used as the numerator of the sum.
for example, 2 / 5 + 1 / 5 = 3 / 5
when two fractions with the same denominator are subtracted, the original denominator is used as the denominator of the difference, The result of subtracting the subtracted molecule from the subtracted molecule is worse than that of the subtracted molecule.
for example, 5 / 7-3 / 7 = 2 / 7
5. It seems that there must be a wallet address on his shop. Go and have a look at the specific arrangement.
6. 2 minutes in 1 hour
23 kilometers, transfer once
1 take subway line 3 (via 13 stops | 38 minutes)
2 walk 199 meters in Hongkou Football field, take subway line 8 (via 2 stops | 9 minutes)
3 get off at Siping Road (exit 3), and walk 406 meters to Shanghai Telecom training center, 879 Tianbao road
23 kilometers, transfer once
1 take subway line 3 (via 13 stops | 38 minutes)
2 walk 199 meters in Hongkou Football field, take subway line 8 (via 2 stops | 9 minutes)
3 get off at Siping Road (exit 3), and walk 406 meters to Shanghai Telecom training center, 879 Tianbao road
7. The taxi fare is about 67 yuan (based on the shortest driving time)
1
line 11 → line 4 → line 10
the whole journey is about 1 hour and 5 minutes / 23.31 km
line 11 Nanxiang subway station
143 meters
walk to Nanxiang station
Nanxiang station
8 stations
(2 entrances) take line 11 (or line 11), Get off at Caoyang Road Station
Caoyang Road Station
173m
walk to Caoyang Road Station
Caoyang Road Station
5 station
take Metro Line 4, get off at hailun Road Station
hailun Road Station
2 station
take Metro Line 10 (or Metro Line 10), Get off at Siping Road Station (exit 2)
Siping Road Station
560m
walk to the canteen of Telecom training center
canteen of Telecom training center
1
line 11 → line 4 → line 10
the whole journey is about 1 hour and 5 minutes / 23.31 km
line 11 Nanxiang subway station
143 meters
walk to Nanxiang station
Nanxiang station
8 stations
(2 entrances) take line 11 (or line 11), Get off at Caoyang Road Station
Caoyang Road Station
173m
walk to Caoyang Road Station
Caoyang Road Station
5 station
take Metro Line 4, get off at hailun Road Station
hailun Road Station
2 station
take Metro Line 10 (or Metro Line 10), Get off at Siping Road Station (exit 2)
Siping Road Station
560m
walk to the canteen of Telecom training center
canteen of Telecom training center
8.
bus line: Metro Line 2 → Metro Line 10, the whole journey is about 26.6km
1. Take Metro Line 2 from xujingdong, pass 1 station to Hongqiao Railway Station
2. Take Metro Line 10, pass 20 stations to Siping Road Station
3. Walk about 730m to 879 Tianbao road
9. First of all, what kind of "metal" or "coal" you are learning or other directions! Mine work is hard! If you want to be comfortable, you shouldn't go to this major!
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