Câu 5:
a) Các phân số bằng \(\dfrac{2}{3}\) là: \(\dfrac{4}{6}\)
b) Các phân số bằng \(\dfrac{5}{3}\) là: \(\dfrac{25}{15};\dfrac{50}{30};\dfrac{75}{45};\dfrac{125}{75}\)
Câu 6:
\(\dfrac{1}{3}=\dfrac{2}{6}=\dfrac{3}{9}=\dfrac{4}{12}=\dfrac{5}{15}=\dfrac{6}{18}\)
\(\dfrac{28}{112}=\dfrac{14}{56}=\dfrac{7}{28}=\dfrac{1}{4}=\dfrac{56}{224}=\dfrac{84}{336}\)
Câu 7:
a) \(\dfrac{2}{3}=\dfrac{12}{18}\) ; \(\dfrac{7}{9}=\dfrac{49}{63}\) ; \(\dfrac{3}{5}=\dfrac{18}{30}\)
b) \(\dfrac{2}{3}=\dfrac{10}{15}\) ; \(\dfrac{5}{9}=\dfrac{25}{45}\) ; \(\dfrac{3}{12}=\dfrac{9}{36}\)
c) \(\dfrac{6}{8}=\dfrac{42}{56}\) ; \(\dfrac{2}{9}=\dfrac{8}{36}\) ; \(\dfrac{49}{56}=\dfrac{7}{8}\)
Câu 8:
a) 5 phân số bằng phân số \(\dfrac{5}{7}\) là: \(\dfrac{10}{14};\dfrac{15}{21};\dfrac{20}{28};\dfrac{25}{35};\dfrac{30}{42}\)
b) 5 phân số bằng phân số \(\dfrac{4}{9}\) là: \(\dfrac{8}{18};\dfrac{12}{27};\dfrac{16}{36};\dfrac{20}{45};\dfrac{24}{54}\)
