Question

One root of 5x^(2) +6x +k =0 is double the other. Find the roots and find the value of k

Answer 1

you have to use the roots and coefficient rules of polynomials i.e. alpha + beta = -(b/a)

Answer 2

A + B = -6/5
and
A*B = k / 5

let A = 2B
so
2B + B = -6/5
2B*B = k/5

you need to solve this system for B and k

Answer 3

i still dont get it