Answer:
Step-by-step explanation:
[tex]\dfrac{1}{3}\\\\\text{List multiples of 3:}\ 0,\ 3,\ 6,\ 9,\ 12,\ \boxed{15},\ 18,\ 21,\ ...\\\\\dfrac{1}{5}\\\\\text{List multiples of 5:}\ 0,\ 5,\ 10,\ \boxed{15},\ 20,\ 25,\ ...\\\\\text{The common denominator is 15.}\\\\\dfrac{1}{3}=\dfrac{1\cdot5}{3\cdot5}=\dfrac{5}{15}\\\\\dfrac{1}{5}=\dfrac{1\cdot3}{5\cdot3}=\dfrac{3}{15}[/tex]