## Algebra 1: Common Core (15th Edition)

The prime factorization is $$2 \times 3 \times 3$$ or $$2 \times 3^2$$
Using the factor tree, you will find that $2$, $3$, and $3$ are the prime numbers that multiply to $18$. $$2 \times 3 \times 3$$ OR $$2 \times 3^2$$