Answer
$84=2^2\cdot3\cdot7$
Work Step by Step
Repeatedly factoring the smallest prime factor from the composite factor, the factors of $84$ are
\begin{array}{l}\require{cancel}
84=2(42)
\\\\
84=2(2)(21)
\\\\
84=2(2)(3)(7)
.\end{array}
Hence, the prime factorization of $84$ is $
84=2^2\cdot3\cdot7
.$
