# The sum of two numbers is 18. The difference of the numbers is 12. How do you find the two numbers?

If you call the smallest number $x$, then the larger number must be $x + 12$ (=difference already expressed)
$x + \left(x + 12\right) = 18 \to 2 x + 12 = 18 \to 2 x = 6 \to x = 3$
The numbers are $3 \mathmr{and} 15$