Question

The sum of two numbers is x. If one of the numbers is 12, what is the other? 12 - x x - 12 12 + x 12 x

Answer 1

Let

a-------> one of the numbers

b------> the other number

we know that

$a+b=x$ ----> equation A

$a=12$

substitute the value of a in the equation A

$12+b=x$

solve for b

Subtract $12$ from both sides

$12+b-12=x-12$

$b=x-12$

therefore

the answer is

The other number is $x-12$

Answer 2

One of the number is 12.
The other number is y.
The sum of the numbers is x.

$12+y=x \\ y=x-12$

The other number is x-12.