## Elementary Algebra

$12$
Factor each number completely to have: $48 = 2 \cdot 2 \cdot 2 \cdot 2 \cdot 3 \\60 = 2 \cdot 2 \cdot 3 \cdot 5 \\84= 2 \cdot 2 \cdot 3 \cdot 7$ Since two 2s and one 3 are common to both, the greatest common factor of the given numbers is: $2 \cdot 2 \cdot 3 = 12$