for what value of,K the factor of xsquare + x-(2K+2)and 2xsquare + Kx-12 is x+4?

(1) x²+x-(2K+2)

it has x+4 as factor which means x+4 is a root of this equation so

substituting 4 in the equation will make it 0

16+4-(2K+2)=0

K=9

(2)2x² + Kx-12  has factor x+4 which means x+4 is a root of this equation so

substituting 4 in the equation will make it 0

2(4)² + K(4)-12  =0

K=5