What is the value of k for which (x1) is a factor of (2x3+9x2+x+k)?

1 Answer
Oct 11, 2017

k=12

Explanation:

f(x)=2x3+9x2+x+k

If (x1) is a factor, then making x=1 would make (x1) equal to 0, and everything else in the equation multiply by that 0, resulting to f(1)=0.

f(1)=213+912+1+k=0

f(1)=2+9+1+k=0

k=(2+9+1)=12