Quy đồng mẫu số các phân số a, 1/2 ,2/3, 3/5 b,1/3 ,3/4, 5/8 c,1/5, 1/6 ,11/30 d,2/3 ,3/4 ,7/12

a)`MSC=30`

$\dfrac{1}{2}$=$\dfrac{1×3×5}{2×3×5}$=$\dfrac{15}{30}$

$\dfrac{2}{3}$=$\dfrac{2×2×5}{3×2×5}$=$\dfrac{20}{30}$

$\dfrac{3}{5}$=$\dfrac{3×3×2}{5×3×2}$=$\dfrac{12}{30}$

b)`MSC=24`

$\dfrac{1}{3}$=$\dfrac{1×4×8}{3×8}$=$\dfrac{8}{24}$

$\dfrac{3}{4}$=$\dfrac{3×3×8}{3×8}$=$\dfrac{18}{24}$

$\dfrac{5}{8}$=$\dfrac{5×4×3}{3×8}$=$\dfrac{15}{24}$

c)`MSC=30`

$\dfrac{1}{5}$=$\dfrac{1×5}{5×6}$=$\dfrac{6}{30}$

$\dfrac{1}{6}$=$\dfrac{1×5}{6×5}$=$\dfrac{5}{30}$

$\dfrac{11}{30}$

d)`MSC=12`

$\dfrac{2}{3}$=$\dfrac{2×4}{3×4}$=$\dfrac{8}{12}$

$\dfrac{3}{4}$=$\dfrac{3×3}{4×3}$=$\dfrac{9}{12}$

$\dfrac{7}{12}$