Answer
$$49x^{2} - 16y^{2}$$
Work Step by Step
We use the FOIL method to evaluate this expression. We multiply each term within the first set of parentheses with each term within the second set of parentheses:
$$49x^{2} + 28xy - 28xy - 16y^{2}$$
Now, we combine like terms:
$$49x^{2} - 16y^{2}$$