# How do you factor x²-2x-8?

May 3, 2018

$\left(x - 4\right) \left(x + 2\right)$

#### Explanation:

${x}^{2} - 2 x - 8$

To factor something, we should first make sure that it is in the form of $a {x}^{2} + b x + c$ to make it easier, which this expression is in.

Then, we have to find two numbers that:

• Add up to $b$ (or in this case, $- 2$)
• Multiply up to $a \cdot c$ (or in this case, $1 \cdot - 8 = - 8$

Those two numbers are $- 4$ and $2$:

• $- 4 + 2 = - 2$
• $- 4 \cdot 2 = - 8$

Now we put them into factored form, which is: $\left(x - 4\right) \left(x + 2\right)$.

Hope this helps!