Question

If 9 and-5 are zeroes of x2+(a+5)x-b. Find value of a and b.

Answer 1

Answer:

let p(x) = x^2+(a+5)bx-b

9 is the zero of polynomial p(x)

then p(9)=0

( 9)^2+(a+5)9b-b=0

81 + 9ab + 45b-b=0

81 + 9ab + 44b = 0......(.i)

Now, -5 is also a zero of the polynomial p (x)

therefore, p(-5)=0

( -5)^2+(a+5)b(-5)-b=0

25 -5ab-25b-b =0

25-5ab-24b = 0 ..........(ii)

Now by solving equation 1 and 2 you will find your answer...