Hmm they're both even numbers so maybe we can start by cutting each number in half.
[tex]\rm \dfrac{18}{48}=\dfrac{9\cdot2}{24\cdot2}=\dfrac{9}{24}[/tex]
18 and 48 had 2 as a common factor.
So factoring a 2 out of each number was the same as cutting each number in half. Try to do something similar with the 9 and 24. They each have something in common.
