Question

Find k so that x-2 is a factor of P(x) = x - kx2 - 4x + 20.​

Answer 1

Answer:

$p(x) = {x}^{3} - k {x}^{2} - 4x + 20 \\ p(2) = {(2)}^{3} - k( {2)}^{2} - 4(2) + 20 \\ = 8 - 4k - 8 + 20 \\ = - 4k + 20$

As x-2 is a factor so p(2)=0

$- 4k + 20 = 0 \\ k = 5$

You have missed the power...

Best of luck dear