Write $A \cap B$ as the union of intervals. Use standard interval notation, that may include round brackets and square brackets. None of your intervals should touch or intersect another.
$$\begin{align*} A &= \Bigl\{ x\in\mathbb{R}\Bigm| x^2 + 3x - 4 \gt 0\Bigr\}\\ B &= \Bigl\{ x\in\mathbb{R}\Bigm| x^2 + 3x - 10\leq 0\Bigr\} \end{align*}$$