Instead of doing it for you, I'll do one exactly like it,
step-by-step. Just follow it as a guide.
I'll do this one instead:
7x-13y = 73
-x-7y=25
Solve the second equation for x
-x-7y=25
-x=25+7y
x=-25-7y
Substitute (-25-7y) for x in the first equation
7x-13y = 73
7(-25-7y)-13y = 73
-175-49y-13y = 73
-175-62y = 73
-62y = 248
y = 248/(-62)
y = -4
Substitute (-4) for y in
x=-25-7y
x=-25-7(-4)
x =-25+28
x = 3
Now do yours step by step the same way.
Edwin