## Elementary Algebra

$135 = 5 \cdot 3 \cdot 3 \cdot 3$
The number ends with 5, so it is divisible by 5. Factor out 5 to obtain: $135= 5 \cdot 27$ 27 is divisible by 3, so factor out 3 to obtain: $135 = 5 \cdot 3 \cdot 9$ 9 is divisible by 3, so factor out 3 to obtain: $135 = 5 \cdot 3 \cdot 3 \cdot 3$