# How do you factor 8x² − 72 ?

Apr 2, 2016

8(x^2-3^2)=8(x+3(x-3)

Apr 2, 2016

$8 \left(x + 3\right) \left(x - 3\right)$

#### Explanation:

First, we can facter $8$ out of the expression as the two terms are multiples of $8$.

$8 {x}^{2} - 72 = 8 \left({x}^{2} - 9\right)$

Now in the brackets we see that we have the difference of 2 squares, (${x}^{2} = {\left(x\right)}^{2}$and $9 = {3}^{2}$) so we can further factorise to:

$8 \left(x + 3\right) \left(x - 3\right)$

And we're done.