Question

the sum of two numbers is 51 and the difference is 15 what are the numbers

Answer 1

x + y = 51
x - y =15

2x = 66
x = 33

33 + y = 51
y = 18

Answer 2

33 and 18, plug it in, and you get 33+18  = 51, and 33-18 = 15