How do you use the remainder theorem to find the remainder for the division (10x^3-11x^2-47x+30)div(x+2)?

2 Answers
Nov 7, 2016

The remainder states that when any polynomial f(x) is divided by x - a, the remainder is f(a).

So, Letting f(x) = 10x^3 - 11x^2 - 47x + 30, we have:

f(-2) = 10(-2)^3 - 11(-2)^2 - 47(-2) + 30

f(-2) = 10(-8) - 11(4) + 94 + 30

f(-2) = -80 - 44 + 94 + 30

f(-2)= 0

The remainder is 0. In other words, x + 2 is a factor of 10x^3 - 11x^2 - 47x +30.

Hopefully this helps!

Nov 7, 2016

This expression has a remainder of zero.
(10x^3-11x^2-47x+30)/(x+2) is equal to (10x^2-31x+15), with no remainder.