Tử số chung là \(2^3.3^2.11=792\)
\(\dfrac{11}{13}=\dfrac{11x72}{13x72}=\dfrac{792}{936}\)
\(\dfrac{6}{8}=\dfrac{6x12x11}{8x12x11}=\dfrac{792}{1056}\)
\(\dfrac{4}{5}=\dfrac{4x18x11}{5x18x11}=\dfrac{792}{990}\)
\(\dfrac{8}{9}=\dfrac{8x9x11}{9x9x11}=\dfrac{792}{891}\)
\(\dfrac{9}{11}=\dfrac{9x8x11}{11x8x11}=\dfrac{792}{968}\)
11 = 1 \(\times\) 11; 6 = 2 \(\times\) 3; 8 = 2 \(\times\) 2 \(\times\) 2; 9 = 3 \(\times\) 3
Vậy tử số chung là: 11 \(\times\) 2 \(\times\)2 \(\times\) 2 \(\times\) 3 \(\times\) 3 = 792
\(\dfrac{11}{13}\) = \(\dfrac{11\times72}{13\times72}\) = \(\dfrac{792}{936}\)
\(\dfrac{6}{8}\) = \(\dfrac{6\times132}{8\times132}\) = \(\dfrac{792}{1056}\)
\(\dfrac{4}{5}\) = \(\dfrac{4\times198}{5\times198}\) = \(\dfrac{792}{990}\)
\(\dfrac{8}{9}\) = \(\dfrac{8\times99}{9\times99}\) = \(\dfrac{792}{891}\)
\(\dfrac{9}{11}\) = \(\dfrac{9\times88}{11\times88}\) = \(\dfrac{792}{968}\)
