<span>f(5)= 2+5 = 7
</span><span>g(5)= 5^2+5 = 25 +5 = 30
</span><span>(f - g) (-5) = 7 - 30 = -23
answer is </span><span>D.-23</span>
9x² - 49
(3x)² - (7)²
= (3x + 7)(3x - 7)
This type of factoring is called Difference of Two Squares
where x² - y² = (x + y)(x - y)
