Question

if 2 of the roots of x^3 + px + q =0 are 3 nd -1 find the 3rd root

Answer 1

Well, give it a name!

Answer 2

i think the point is that there is no \(x^2\) term

Answer 3

multiply out
\[(x-3)(x+1)(x-r)\] and make sure the coefficient of the \(x^2\) term is zero