Question

How do I solve this using elimination?

80x + 45y = 645
x + y = 12

Answer 1

If you combine like terms and do them differently you will have 3 different answers

Answer 2

x + y = 12 / x (-45);
Then, -45x - 45y = -540;
We have 80x + 45y = 645 and
-45x - 45y = -540
________________
35x = 105;
Finally, x = 105÷35;
x = 3;
y = 12 - 3;
y = 9;