Ta có:
\(\dfrac{54}{90}=\dfrac{3}{5}\)
\(\dfrac{180}{288}=\dfrac{5}{8}\)
\(\dfrac{60}{135}=\dfrac{4}{9}\)
Mẫu số chung là: 360
\(\dfrac{3}{5}=\dfrac{3.72}{5.72}=\dfrac{216}{360}\)
\(\dfrac{5}{8}=\dfrac{5.45}{8.45}=\dfrac{225}{360}\)
\(\dfrac{4}{9}=\dfrac{4.40}{9.40}=\dfrac{160}{360}\)