Answer:
2x - 11y + 21
Explanation:
First, I would rewrite the equation so that like terms are right next to each other.
-5x + 7x - 9y - 2y + 18 + 3
Now, complete the operations like normal.
-5x + 7x = 2x
-9y - 2y = -11y
18 + 3 = 21
Since you cannot simplify anymore as there are no like terms left to combine, you are left with your equation and final answer:
2x - 11y + 21