Answer
$x = 5$ or $x = -4$
Work Step by Step
We have a quadratic expression in the form $x^2 + bx + c$.
Find factors of $c$, which is $-20$ , whose sum is $b$, which is $-1$ in this case.
List of possible factors:
$-5$ and $4$
$-10$ and $2$
$-20$ and $1$
The first pair will work.
Rewrite the equation using the factors:
$(x - 5)(x + 4) = 0$
Use the Zero Product Property to set each factor equal to $0$ and solve:
First factor:
$x - 5 = 0$
$x = 5$
Second factor:
$x + 4 = 0$
$x = -4$