Question

If -3 is a rot of the equation x2 + kx +15 =0 and the equation 2x2 + kx + p = 0 has equal roots find the value of p

Answer 1

Answer:

The answer is simple

Step-by-step explanation:

Given ,

equations x2+kx+15=0 and. 2x2+kx+p=0

given that (-3) is a equal root of both the equations,

Let x2+kx+15----eq(1) and 2x2+kx+p=0-----eq(2),

Let x=(-3)----(3)

From eq(1)..

f(x)=x2+kx+15=0

Substitute (3)in eq(1)

f(-3)=(-3)2+k(-3)+15=0

= 9-3k+15=0

= 24-3k=0

=) k= 8.

we have x=(-3) and k=8.

Substitute this values in eq(2).

From eq(2)

let g(x)=2x2+kx+p=0

= 2(-3)2+8(-3)+p=0

= 18-24+p=0

= -6+p=0

= p= 6..

therefore the value of p = 6.