Question

What’s the explanation

Answer 1

Answer:

x³ + 2x² - 19x - 20

Step-by-step explanation:

x + 1 = 0

x = -1

Substitute x = (-1) in the polynomial

x³ + 2x² - 19x - 20 = (-1)³ + 2*(-1)² - 19 *(-1) - 20

                            = -1 + 2 +19 - 20

                             = -1 - 20 + 2 + 19

                              = -21 + 21 = 0

So, (x + 10 ix a factor of  x³ + 2x² -19x - 20