Question

if alpha and bita are zeroes of x^2-x+k and 3 alpha+ 2 bita=20.find the value of k

Answer 1

I think it answer for ur question........check it yar

Answer 2

Given alpha and beta are the zeroes of the given polynomial f (x) = x²-x+k , such that
3 alpha + 2 beta = 20
beta = 20 - 3 alpha / 2 .......eq (1)

we know that the sum of the zeroes of a quadratic eq is given by
alpha + beta = -b/a
alpha + 20 - 3alpha /2 = - (-1). ( from eq 1)
2 alpha + 20 - 3 alpha = 2
20 - alpha = 2
20 - 2 = aplha
18 = aplha. ..... eq 2

and the product of zeroes is given by
alpha × beta = c/a
18 × 17 = k
306 = k
ans ...

Hope it will be contented...