Question

if (-4) is a root of quadratic equation 5x²+px-20=0 and the quadratic equation p(x²-2x)+k=0 then fund the value of k and p​

Answer 1

Answer:

Since −5 is a root of the equation 2x

2

+px−15=0. Therefore,

2(−5)

2

−5p−15=0⇒p=7

Putting p=7 in p(x

2

+x)+k=0 we get

7x

2

+7x+k=0

Here ,a=7,b=7;c=k

This equation will have equal roots, if

Discriminant =b

2

−4ac=0 ⇒49−4×7×k=0⇒k=

28

49

⇒k=

4

7