Answer
$$25x^2 - 16$$
Work Step by Step
We will use the FOIL method to multiply the two binomials together and expand the expression. In the FOIL method, we first multiply the first terms, then the outside terms, then the inside terms, and, finally, the last terms:
$$(5x)(5x) + (5x)(-4) + (4)(5x) + (4)(-4)$$
Let's multiply to simplify the expression:
$$25x^2 - 20x + 20x - 16$$
Combine like terms:
$$25x^2 - 16$$
