Question

Given f(x) = 3x^2 + kx-1, and the remainder when f(x) is divided by x + 4 is 27, then what is the value of k?

Answer 1

k=10

do long or synthetic division. the quotient = 3x + 22 with remainder 81

with long division first divide x into 3x^2 to get 3x. Then

3x times (x-4) = 3x^2-12x

subtract that from 3x^2+kx to get (k-12)x bring down the -7 to get

(k-12)x -7

you want a remainder of 81, so you want -4 times a constant to = -88 (-7-(-88)=81

4 x 22 =88. 22 is the constant

22=12+k

k=10

Explanation:

lmk if i helped!