Question

In the polynomial below, what number should replace the question mark to produce a difference of squares? X^2 + ?x -49 A. 0 B. 14 C. 49 D.7

Answer 1

A

Explanation:

The difference of squares formula is a² - b² = (a + b)(a - b). We want this polynomial to be in the form a² - b². We notice that x² and 49 are perfect squares already which means that we don't need the x term. To get rid of it, its coefficient must be 0 because 0 times anything is 0, thus the x term will be removed and we'll be left with x² - 49 which is a difference of squares.