Question

a) Nêu hai phân số bằng mỗi phân số sau: \(\dfrac{5}{4};\dfrac{9}{12}\)

b) Rút gọn các phân số sau: \(\dfrac{24}{32};\dfrac{14}{35};\dfrac{30}{25};\dfrac{63}{36}\)

Answer 1

a) \(\dfrac{5}{4}=\dfrac{5\times3}{4\times3}=\dfrac{15}{12};\dfrac{5}{4}=\dfrac{5\times5}{4\times5}=\dfrac{25}{20}\)

Hai phân số bằng phân số \(\dfrac{5}{4}\) là \(\dfrac{15}{12}\) và \(\dfrac{25}{20}\)

\(\dfrac{9}{12}=\dfrac{9:3}{12:3}=\dfrac{3}{4};\dfrac{9}{12}=\dfrac{9\times2}{12\times2}=\dfrac{18}{24}\)

b) \(\dfrac{24}{32}=\dfrac{24:8}{32:8}=\dfrac{3}{4}\)

\(\dfrac{14}{35}=\dfrac{14:7}{35:7}=\dfrac{2}{5}\)

\(\dfrac{30}{25}=\dfrac{30:5}{25:5}=\dfrac{6}{5}\)

\(\dfrac{63}{36}=\dfrac{63:9}{36:9}=\dfrac{7}{4}\)