The system of equations known about a, b, a 3b 3 2m, 3a b 2m

a+3b=3+2m，3a+b=-2m+6

The sum of the two formulas.

4a+4b=3+2m-2m+6

4(a+b)=9

a+b=9/4=

Absolutely.

Because a+3b=3+2m

So 3a+9b=9+6m

So 3a+9b-(3a+b)=9+6m-(-2m+6)8b=8m+3

Because 3a+b=-2m+6

So 9a+3b=-6m+18

9a+3b-(a+3b)=-6m+18-(3+2m)8a=-8m+15

So 8a+8b=8

a+b=1

a+2b=3-m,2a+b=-m+4

The sum of the two formulas.

3a+3b=7-2m

a+b=7/3-2m/3

It is estimated that the second one may be miswritten, and it is 2a+b=m+4

In this case, a+b=7 3

Summary. The method of solving binary linear equations is generally to eliminate the binary linear equation and turn it into a univariate linear equation to solve. There are two ways to eliminate elements:

1. Addition, subtraction, and elimination method; 2. Substitution of the elimination method. 1. The addition and subtraction method cancels one of the unknowns by adding or subtracting the two equations in the equation system, so as to achieve the purpose of eliminating the element, and the unknown number in the equation system is solved one by one. 2. Substitution of the elimination method.

Passed"Substitution"Eliminate an unknown number and convert the system of equations into a one-dimensional equation to solve, this solution method is called substitution elimination method, referred to as substitution method.

2a-b=3+a+b=3 equations.

2a-b=3+a+b=3 equations.

Good. Thank you.

The method of solving binary linear equations is generally to eliminate the binary linear equation and turn it into a univariate linear equation to solve. There are two ways to eliminate the element: 1. Addition and subtraction elimination method; 2. The car section has been used in the past dynasties.

1. The addition and closure search and subtraction method uses the method of addition or subtraction to cancel one of the unknowns of the two equations in the equation system, so as to achieve the purpose of eliminating the element, and reduce the number of unknowns in the equation system from more to less, and solve the burning deficiency one by one. 2. Substitution elimination method: passed"Substitution"Eliminate an unknown number and convert the system of equations into a one-dimensional equation to solve, this solution method is called substitution elimination method, referred to as substitution method.

3a ten 2b = 2,

A 2a ten b = 2,

Solution: Definitely.

b=2a+2，③

Substitute the hall into it.

3a ten 2 (2a ten 2) = 2, 3a ten 4a ten 4 = 2, 7a = a dress with the beam 2, a = a 2 chaotic tong 7.

Substitute a = a 2 7 to get it.

b = a 2 7 2 ten 2 = 10 7.

So the solution of the original system of equations is:

A = a 2 7, b = 10 7.

Solve systems of equations.

a-b=2m+1

a+b=4m+3

A=3m+2, B=M+1 is substituted into 2A-3B=7 to get 6M+4-3M-3=3M+1=7, so M=2

2) Substituting a=3m+2, b=m+1 into a+2b<12 to get 5m+4<12, m<8 5, and solving the inequality group {x-m<0

4x+3>2x-1 gives -2 because, the solution inequality group has three integer solutions, which have three integer solutions which are -1, 0, 1Therefore, the value range of 1m is 1

Solve systems of equations.

a-b=2m+1

a+b=4m+3

A=3m+2, B=M+1 is substituted into 2A-3B=7 to get 6M+4-3M-3=3M+1=7, so M=2

2) Substituting a=3m+2, b=m+1 into a+2b<12 to get 5m+4<12, m<8 5, and solving the inequality group {x-m<0

4x+3>2x-1 gives -2 because, the solution inequality group has three integer solutions, which have three integer solutions which are -1, 0, 1So if the value range of 1m is 1, can it solve your problem?

(1) The system of equations known about a and b a-b=2m+1 a+b=4m+3 is solved to obtain a=3m+2, b=m+1

So 2a-3b=2(3m+2)-3(m+1)=3m+1=7, so m=2

2) If a+2b 12

then 3m+2+m+1 12

So m 9 4

x-m＜0 4x+3＞2x-1

x＜m x＞-2

So -2 x m

Because the group of inequalities has three integer solutions.

So the solution of these 3 integers is -1, 0, 1

So 1 m 2

The range of values of m after taking the intersection is.

If you don't understand, please ask, and I wish you a happy study!

a+2b=3-m

2a+b=-m+4

- A-b=-m+4-(3-m)=4-3=1

It is not easy to answer the question, if you are dissatisfied, please understand

a+2b=3-m，2a+b=-m+4

The sum of the two formulas.

3a+3b=7-2m

a+b=7/3-2m/3

It is estimated that the second one may be miswritten, and it is 2a+b=m+4

In this case, a+b=7 3