if a number is added to its square, the result is 72. find the number

if a number is added to its square, the result is 72. find the number.

Let the number be n. We're given:
n + n^2 = 72

Subtract 72 from each side, we get:
n^2 + n - 72 = 0

This is a quadratic equation. We type this equation into our search engine, and we get:
n = 8 and n = -9