Hello

Let $\displaystyle \alpha,\beta$ be the two solutions of the quadratic equation

$\displaystyle 3x^2+6x+7=0.$

Then the value of $\displaystyle (2\alpha-\beta)(2\beta-\alpha)$ is ?

How can I get the values for $\displaystyle \alpha$ and $\displaystyle \beta$? After trying with the quadratic ecuation, I was always getting a negative value on the $\displaystyle sqrt{}$ section.

Thanks.