I’m thinking of two numbers. Their sum is 20. Their difference is 4. What are the two numbers?

Answer 1

n + m = 20

n - m = 4

Add the two equations and get

2n = 24

n = 12

Plug n=12 into either equation and solve for m. Using the top equation,

12 + m = 20

m = 8

Test the answer.