Question

Use substition.
2m+n=1
m-n=8

Answer 1

2m+n=1
m-n=8 ----> m=8+n


2(8+n)+n=1
16+2n+n=1
3n=-15
n=-15

plug that in into one of the equations

m-(-15)=8
m+15=8
m=-7

Answer 2

The answer should be (3,-5). Well at least that's what it says in the back of the book.

Answer 3

@SolomonZelman
3n = -15
n=-5

Answer 4

Yeah, sorry for this silly mistake!

Answer 5

My 50th day, I am kind of new to the website...