Answer:
x = 13 and y = 5
Step-by-step explanation:
x + y = 18
x - y = 8
Step 1: Find y
x = 18 - y
(18 - y) - y = 8
18 - y - y - 18 = 8 - 18
-2y / -2 = -10 / -2
y = 5
Step 2: Plug into x + y = 18 to get x
x + 5 - 5 = 18 - 5
x = 13
Answer: x = 13 and y = 5