Question

question
factor.
$x^2 - 3x - 18$

Explanation:

Step1: Find pair of factors of -18

We need two numbers that multiply to $-18$ and add to $-3$. These numbers are $-6$ and $3$, since $(-6) \times 3 = -18$ and $(-6) + 3 = -3$.

Step2: Split middle term and factor

Rewrite the quadratic using the found numbers, then factor by grouping:

$$\begin{align*} x^2 - 3x - 18 &= x^2 - 6x + 3x - 18 \\ &= x(x - 6) + 3(x - 6) \\ &= (x - 6)(x + 3) \end{align*}$$

Answer:

$(x - 6)(x + 3)$