Question

Write an equation for the following, then solve. Show your work.
If a number is subtracted from its square, the result is 90. Find the number(s).

Answer 1

Answer:

x = -9, 10

Step-by-step explanation:

$x^2 - x = 90$

Solve this as a quadratic equation, so subtract 90 from both sides:

$x^2-x-90=0$

Factoring:

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

This means that:

$x + 9 = 0\\\\x=-9\\or\\x - 10 = 0\\x = 10$

x can be -9 or 10.