Answer: 1/3
Step-by-step explanation:
When adding or subtracting fractions, they must have the same denominator.
[tex]\dfrac{5}{9}-\boxed{\dfrac{?}{?}}=\dfrac{12}{54}\\\\\\\dfrac{5}{9}\bigg(\dfrac{6}{6}\bigg)-\boxed{\dfrac{?}{?}}=\dfrac{12}{54}\\\\\\\dfrac{30}{54}-\boxed{\dfrac{?}{?}}=\dfrac{12}{54}\\\\\\\dfrac{30}{54}-\boxed{\dfrac{18}{54}}=\dfrac{12}{54}\\\\\\\text{Simplify}\quad \dfrac{18}{54}\div \dfrac{18}{18}\quad =\large\boxed{\dfrac{1}{3}}[/tex]
