Answer
$(x-1)(x+8)$
Work Step by Step
To factor a second-degree polynomial $x^2 +7x - 8$, we have to find integers whose product is $-8$ and whose sum is $7$. That is, we have $-1$ and $8$ where $-1+8=7$ and $-1\times (8)=-8$. Thus:
$$
x^2 +7x - 8=(x-1)(x+8)
.$$
