Answer
-1 and 2 are solutions of the quadratic equation $x^2-x-2=0$.
Work Step by Step
RECALL:
If $(x-a)(x-b)=0$, then $x=a$ and $x=b$ are solutions of the equation $(x-a)(x-b)=0$.
Since $-1$ and $2$ are solutions of the quadratic equation, then the equation must be:
$(x+1)(x-2)=0$
Multiply the binomials to have:
$\\x(x-2) +1(x-2)=0
\\x^2-2x+x-2=0
\\x^2-x-2=0$
