-2x + y = 9 (eq. 1)
3x - 7y = 3 (eq. 2)
Isolate y in the first equation, as follows:
y = 9 + 2x (eq. 3)
Replace this in the second equation:
3x - 7(9 + 2x) = 3
3x - 7*9 - 7*2x = 3
3x - 63 - 14x = 3
-11x = 3 + 63
x = 66/(-11)
x = -6
Replacing this result into the third equation:
y = 9 + 2*(-6)
y = -3
Then, the answer is (-6, -3)
