# How do you factor the expression  x² - 8x + 7?

##### 1 Answer
Apr 16, 2018

${x}^{2} - 8 x + 7 = \left(x - 1\right) \left(x - 7\right)$

#### Explanation:

Consider the given expression:
${x}^{2} - 8 x + 7$

Use middle term splitting. Choose factors such that their product is +7 and sum (-8).
Thus, we get the numbers (-1) and (-7).
Then,
${x}^{2} - x - 7 x + 7$
$x \left(x - 1\right) - 7 \left(x - 1\right)$
$\left(x - 1\right) \left(x - 7\right)$