Ohhh ok thank you can't believe I didn't see that.Yes the root you are given is gamma. You could solve simultaneously. Just check your last equation - should your second and third terms be the same?
BUT, you know that gamma is 3 and you are asked to find the sum and product of alpha and beta, NOT alpha and beta themselves. You really only nee the first 2 equations.
Make sure you check your answer by substituting those back into the original equation.Ohhh ok thank you can't believe I didn't see that.