Question

1) x-y = 1
2x + y=8

2) y= 2x +3
y= 4x + 4

3) 2x + 7y = 8
x+5y=7

4) y=4x+4
y=2x + 8

5) 4x-7y=9
y=x-3
?????

Answer 1

so what you need to do ? solve theses systems of equations ?

using substitution or elimination method ?