## Elementary Algebra

$84=2 \cdot 2 \cdot 3 \cdot 7$
The number is even, so factor out 2 to obtain: $84= 2 \cdot 42$ 42 is even, so factor out 2 again to obtain: $84 = 2 \cdot 2 \cdot 21$ 21 is divisible by 3 so factor out 3 to obtain: $84=2 \cdot 2 \cdot 3 \cdot 7$