Question

By using the remainder theorem, determine the remainder when

Answer 1

Answer:

C) -123

Step-by-step explanation:

x + 4 = 0

x = -4

3(-4)³ − (-4)2 − 20(-4) + 5

-123

Answer 2

Answer:

-123

Step-by-step explanation:

The remainder theorem says that when a polynomial is divided by a linear factor x - c (note the minus sign), the remainder is the value of the polynomial at x = c.

When a polynomial P(x) is divided by x - c, the remainder is P(c).  In other words, to find the remainder, plug in c for x.

You're dividing by x + 4 which is the same thing as x - (-4) -- the role of c is being played by -4.

3(–4)^3 – (–4)^2 – 20(–4) + 5 = –123