Question

A certain number added to its square is equal to 90. What is/are the number(s) that work?

Answer 1

Answer:

9,-10

Step-by-step explanation:

Let u be a number.

$u + {u}^{2} = 90$

$u {}^{2} + u - 90 = 0$

$(u + 10)(u - 9) = 0$

$u = - 10$

or

$u = 9$

9, -10

Answer 2

9,-10 the guy above got what I got