Find two numbers, if their sum is 93 and their difference is 9.

Answer 1

Let's call one of the numbers x, the other one y.

x+y=93

x-y=9

If you add these equations up, you get x+y+x-y=93+9

2x = 102

x=51

If x=51, then:

x+y=93

51+y=93

y=93-51

y=42

So one of the numbers is 51, the other one is 42.

Hope this helps :)