Answer
$4p^{4} - 49q^{2}$
Work Step by Step
We use the formula for the difference of squares to apply to this question.
The difference of squares formula is:
$(a-b) (a+b) = a^{2} - b^{2}$
In the given formula let $2p^{2}$ represents a and 7q represents b.
$(2p^{2}-7q) (2p^{2}+7q) = (2p^{2})^{2} - (7q)^{2}$
= $4p^{4} - 49q^{2}$