you can isolate y on both sides, getting:
2x-17=y and x-10=y
Then, make the two y equal each other, and solve the equation
2x-17=x-10
The answer would be x=7.
then, plut in the amount into one of the equations:
x-y=10
7-y=10
y=-3
T
Therefore, the answer is x=7 and y = -3, or (7,-3)