Question

How do you find the remainder when `x^3+8x^2+11x-20` is divided by x-5?

Answer 1

When `x^3+8x^2+11x-20` is divided by `(x-5)`, the remainder is `360`

Explanation:

According remainder theorem, if a polynomial `f(x)` is divided by a binomial of degree `1` i.e. `(x-a)`, the remainder is `f(a)`.

Hence, when `x^3+8x^2+11x-20` is divided by `(x-5)`, the remainder is

`f(5)=5^3+8xx5^2+11xx5-20`

= `125+8xx25+55-20`

= `125+200+55-20`

= `360`