a: 1/2=15/30
2/3=20/30
3/5=18/30
b: 1/3=8/24
3/4=18/24
5/8=15/24
c: 1/5=6/30
1/6=5/30
1/30=1/30
\(a,MSC:30\\ \dfrac{1}{2}=\dfrac{1\times15}{2\times15}=\dfrac{15}{30};\dfrac{2}{3}=\dfrac{2\times10}{3\times10}=\dfrac{20}{30};\dfrac{3}{5}=\dfrac{3\times6}{5\times6}=\dfrac{18}{30}\\ b,MSC:24\\ \dfrac{1}{3}=\dfrac{1\times8}{3\times8}=\dfrac{8}{24};\dfrac{3}{4}=\dfrac{3\times6}{4\times6}=\dfrac{18}{24};\dfrac{5}{8}=\dfrac{5\times3}{8\times3}=\dfrac{15}{24}\\ c,MSC:30\\ \dfrac{1}{5}=\dfrac{1\times6}{5\times6}=\dfrac{6}{30};\dfrac{1}{6}=\dfrac{1\times5}{6\times5}=\dfrac{5}{30};\dfrac{11}{30}=\dfrac{11}{30}\\ d,MSC:12\\ \dfrac{2}{3}=\dfrac{2\times4}{3\times4}=\dfrac{8}{12};\dfrac{3}{4}=\dfrac{3\times3}{4\times3}=\dfrac{9}{12};\dfrac{7}{12}=\dfrac{7}{12}\)
