# How do you factor completely x^2– 7x + 18?

Sep 19, 2016

The given expression does not factor. Maybe these were meant?
${x}^{2} - 7 x - 18 = \left(x + 9\right) \left(x - 2\right)$
${x}^{2} - 9 x + 18 = \left(x - 3\right) \left(x - 6\right)$

#### Explanation:

This expression does not factor- there might be a typo perhaps?

The following are possibly what was meant?

${x}^{2} - 7 x - 18 = \left(x - 9\right) \left(x + 2\right)$
Factors of 18 which subtract to make 7, are 9 and 2.

OR

${x}^{2} - 9 x + 18 = \left(x - 3\right) \left(x - 6\right)$
Factors of 18 which ADD to give 9 are 6 and 3

Hope this helps.