Answer:
x^2 +4x-21
Step-by-step explanation:
(x-3) (x+7)
FOIL
first x*x = x^2
outer: 7x
inner: -3x
last: -3*7=-21
Add them together
x^2 +7x-3x -21
The answer should be D.
(x - 3)(x + 7)
= x² - 3x + 7x - 21 (using the FOIL technique)
= x² + 4x - 21
Hope this helps! Stay safe in quarantine!
