Question

If -5 is the root of the quadratic eqn 2x²+px-15=0and the quadratic equation p(x²+x) k=0 has the equal roots find the value of k

Answer 1

2x^2+px-15=0

Given root is -5

2(-5)^2+p(-5)-15=0

50-5p-15=0

5p=35

p=7

pk(x^2+x)

7kx^2 + 7kx has real roots.

It means b^2-4ac=0