X+y=7 X-y=1

Ouch!

Always check your answer!

x+y=7

x-y=1

x-1=y (from the second equation)

substitute in the first equation.

x+(x-1)=7

2x=6

x=3

I think Anonymous forgot to check his/her answer here

Taking it from this point, we have

x + ( x - 1)  = 7

2x - 1  = 7    add 1 to both sides

2x = 8     divide both sides by 2

x = 4

And using x + y = 7

4 + y = 7   ....  so.....y = 3

And the answer is  (x, y) = (4, 3)

X=4 

y=3

4+3=7 4-3=1