Question

Use the substitution method to solve the linear equation to find the solution. 7a= 5-b, 7a= 2-b. Will it be one solution,infinitely or on solution?

Answer 1

do you have any idea?

Answer 2

7a= 5-b,
Can be rewritten as
b= **5 - 7a**

so if I sub that into
7a= 2-b
[i have a value for b now]

7a = 2 - **[ 5 - 7a ]**

7a = 2 - [ 5 - 7a ]
7a = 2 - 5 + 7a
move 7a to other side
uh oh
that makes
0 = 3

not possible.
so no solution

Answer 3

congrat!

Answer 4

look at this, 7a = 5-b
also, 7a = 2-b
then ---------------
5-b= 2-b
plus b to both sides 5-b+b= 2-b+b
----> 5=2 ???!!!! impossible ---> no solution