Hello from MrBillDoesMath!
Answer:
x = 4, y = 5
Discussion:
-2x + 5y = 17 (*)
x + y = 9 (**)
Multiplying (**) by 2 gives
2x + 2y = 18 (***)
Adding (*) and (***) gives
(-2x + 5y) + (2x + 2y) = 17 + 18 =>
(-2x + 2x) + (5y + 2y) =35 => as -2x + 2x = 0 and 5y +2y = 7y
0 + 7y = 35 => divide both sides by 7
y = 35/7 = 5
Substituting y = 5 in (**) gives x + y = 9 or x + 5 = 9 => x = 9-5 = 4
Thank you,
MrB