## Algebra: A Combined Approach (4th Edition)

$2 \times 3 \times 7$
$42$ is the product of $6$ and $7$ so, $6 \times 7 = 42$ where 7 is prime and 6 is not, however $6 = 2 \times 3$ so we can write, $2 \times 3 \times 7 = 42$ and now all the factors are prime