Question

If alpha and beta are the zeros of x^2 + 2X + 15 , find the value of 1/alpha + 1/beta - 2 alpha × beta

Answer 1

I am assuming the eqn to be

X2 + 2x -15 =0
alpha + beta = -b/a = -2/1
Alpha * beta = c/a = -15
Put value of alpha = -15/beta in 1st eqn.
Equation becomes
Beta2 +2beta -15 =0
After solving
Beta = 3 , alpha =-5

Now put value and get the answer

Answer 2

hey sorry my internet connection is slow i am not send attachment...
a+b=-b/a = -2/1. =-2
a*b=c/a=. 15/1 =15
so , value of

1/a + 1/b -2ab
=} a+b/ab -2ab
=-2/15 -2*15
=}-2/15-30/1
=}-452/15... answer...