Question

what is 18/42 in it's simplest form?

Answer 1

$\dfrac{18}{42}=\dfrac{3\cdot6}{7\cdot6}=\dfrac{3}{7}$

Answer 2

Well, you can divide both numbers by 6.
18/6=3
42/6=7.
You have the simplest form in the simplest way!!
Your answer is 3/7.
Hope this helped!!