Question

How do you factor the expression `9x^2+9x+2`?

Answer 1

You look for its roots with the quadratic formula.

Explanation:

We first need `Delta = b^2 - 4ac = 9`. So there are two real roots.

By the quadratic formula, a root is given by the expression `(-b +- sqrtDelta)/2a`. We apply it here.

`x_1 = (-9 - 3)/18 = -2/3` and `x_2 = (-9 + 3)/18 = -1/3`.

So this polynomial is equal to `9(x + 2/3)(x + 1/3)`.