\(\dfrac{15}{30};\dfrac{10}{30};\dfrac{6}{30}\)
MC LÀ 30
1/2=1 x 15/ 2x15 =15/30
1/3=1x10/3x10=10/30
1/5=1x6/5x6=6/30
\(\dfrac{1}{2}\)=\(\dfrac{1x3x5}{2x3x5}\)=\(\dfrac{15}{30}\) ; \(\dfrac{1}{3}\)=\(\dfrac{1x2x5}{3x2x5}\)=\(\dfrac{10}{30}\); \(\dfrac{1}{5}\)=\(\dfrac{1x2x3}{5x2x3}\)=\(\dfrac{6}{30}\)