Question 721712
if "a number" is x, then its square would be {{{x^2}}}. And "When a number x is added to its square, the total is 90" translates into:
{{{x + x^2 = 90}}}<br>
This is a quadratic equation so we want it in standard form. Subtracting 90 and rearranging the terms we get:
{{{x^2+x-90=0}}}
Factor:
(x+10)(x-9) = 0
From the Zero Product Property we get:
x+10 = 0 or x-9 = 0
Solving these:
x = -10 or x = 9
These are both solutions to the problem. Check them if you like.