Plug x-7 in for y in the first equation so
Divide by 2:
I can see that this factorises to
therefore either x-4=0 or x-3=0 and therefore x = 4 or x=3.
We then put these back into y = x-7
y = 4-7 = -3 or y = 3-7 = -3.
Our solutions are therefore x=4, y=-3 or x=3, y=-4. There are two pairs of answers for this