Answer
$(x+5)(x-3)$
Work Step by Step
RECALL:
A trinomial of the form $x^2+bx+c$ (leading coefficient is 1) can be factored if there are factors of $c$ (say, $d$ and $e$) whose sum is equal to $b$.
The trinomial factors as $(x+d)(x+e)$
The given trinomial has a leading coefficient of 1 so the factoring technique mentioned above may be used.
Look for factors of $-15$ whose sum is equal to $2$.
Note that $(5)(-3)) = -15$ and $5+(-3)=2$
This means that the given trinomial factors as $(x+5)[x+(-3)]= (x+5)(x-3)$.
