# How do you factor completely 5a-15a^2?

Jun 28, 2016

5a(1-3a)

#### Explanation:

There is a common factor of 5a in both terms which can be 'taken out'.

$\Rightarrow 5 a - 15 {a}^{2} = 5 a \left(1 - 3 a\right)$

This may be checked by distributing the bracket.

$5 a \left(1 - 3 a\right) = \left(5 a \times 1\right) - \left(5 a \times 3 a\right) = 5 a - 15 {a}^{2}$