Question

x² + px + q = (x-4) (x+5) , write the value of p

Answer 1

Step-by-step explanation:

−4 is the root of x

2

+px−4=0

⇒(−4)

2

+p(−4)−4=0

⇒16−4p−4=0

⇒12=4p

so p=3

x

2

+px−q=0

⇒x

2

+3x+q=0

It has equal roots so D=0

b

2

−4ae=0

9−4q=0

so q=

4

9

So p=3 & q=

4

9

.

solution