If x-2 is a factor of kx^2 + kx + 20 then k=
A) 3
B) 10
C) 10/3
D) -3/10
E)-10/3

Ive tried to work them all out on my own but none of them seem to work for me... please help :3

Question

If x-2 is a factor of kx^2 + kx + 20 then k=
A) 3
B) 10
C) 10/3
D) -3/10
E)-10/3

Ive tried to work them all out on my own but none of them seem to work for me... please help :3

uri · Answer

Show your work

anonymous · Answer

i just plugged in each answer choice in to the equation and tried to factor it but i never got x-2. and then I tried foiling x-2 and figuring out the other factor in order to get the equation but niether worked and its all in a spiral notebook

ganeshie8 · Answer

use this :-
if x-2 is a factor, then plugging x = 2 in the given quadratic gives 0

plug x = 2 in given quadratic, set it to 0 :-

k(2)^2+k(2) + 20 = 0

ganeshie8 · Answer

simplify and solve k

anonymous · Answer

thank you so much!
that makes a lot more sense than what i was doing :p

ganeshie8 · Answer

glad to hear :) wat did u get for k ?