Question

Dividing the polynomial P(x) by x + 2 yields a quotient Q(x) and a remainder of 8. If Q(2) = 5, find P(-2) and p(2)​

Answer 1

Answers:

P(-2) = 8

P(2) = 28

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Step-by-step explanation:

Part A) Find P(-2)

We'll divide P(x) over (x+2) to get a quotient Q(x) and remainder 8 like so

P(x)/(x+2) = quotient + remainder/(x+2)

P(x)/(x+2) = Q(x) + 8/(x+2)

When multiplying both sides by (x+2), it clears out the fractions and we're left with this

P(x) = (x+2)*Q(x) + 8

From here, plug in x = -2 and simplify

P(x) = (x+2)*Q(x) + 8

P(-2) = (-2+2)*Q(-2) + 8

P(-2) = (0)*Q(-2) + 8

P(-2) = 0 + 8

P(-2) = 8

Luckily we don't need the value of Q(-2) since it cancels out with the zero.

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Part B) Find P(2)

This time we'll plug in x = 2 and we'll get...

P(x) = (x+2)*Q(x) + 8

P(2) = (2+2)*Q(2) + 8

P(2) = 4*Q(2) + 8

P(2) = 4*5 + 8

P(2) = 20+8

P(2) = 28