Question

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

Answer 1

putting x = -5,

you get p = 7, in the first equation.

Now, put the value of p = 7 in second equation. so you get,

7(x^x)+k=0.

now both the equations have same roots.

So, put X=-5 in second equation.

Then you will get,

k=-7\((-5)^5)

therefore the value of k is 7\3125.