Answer
$x^2-2x-15=0$
Work Step by Step
As we are given that solution set : {$-3,5$}
This implies that $x=-3,5$
As per zero-product reverse property, we have $(x+3)(x-5)=0$
Now, apply FOIL METHOD
$(x+3)(x-5)=0 \implies x^2-5x+3x-15=0$
or, $x^2-2x-15=0$
