Question

if -5 is a root of the quadratic equation 2x^2+2px-15=0 and the quadratic equation P(x^2+x)+k=0 has equal roots, find the value of k.​

Answer 1

z(x+5)+y(x+5)

z=2x

y=-3

therefore we get p=7/2

poly(x^2+x) =

2(x^2+x)^2+7(x^2+x)-15+k=0

given that ur has equal roots therefore D=0

√b^2-4ac =0

b^2=4ac

49(x^4+x^2+2x^3)=8k-120

49(x^4+x^2+2x^3)/8+15=k

idk if it's correct maybe I got something wrong so please reply