Question

the sum of two numbers is 136. one number is 51. what is the other number? what are the common factors of these two numbers?

Answer 1

You said that 51 + (the other number) = 136 .

This is an equation.
I can do anything I want to one side of it,
as long as I do exactly the same thing to
the other side.

Let's subtract 51 from each side: (the other number) = 136 - 51

= 85 .

The factors of 51 are 1, 3, 17, and 51 .

The factors of 85 are 1, 5, 17, and 85 .

The common factors are 1 and 17 .