Question

The sum of two numbers is 55 and the difference is 21. what are the numbers?

Answer 1

A) x + y = 55
B) x -y =21

Adding both equations:
2 x = 34
x = 17
y = 38

Answer 2

x + y = 55
x - y = 21
2x = 76
x =38
38 + y = 55
y =17
(38, 17)