Question

Answer 1

\(\dfrac{18}{21}=\dfrac{18:3}{21:3}=\dfrac{6}{7}\)

\(\dfrac{35}{42}=\dfrac{35:7}{42:7}=\dfrac{5}{6}\)

\(\dfrac{115}{225}=\dfrac{115:5}{45:5}=\dfrac{23}{45}\)

Answer 2

\(\dfrac{18}{21}=\dfrac{18:3}{21:3}=\dfrac{6}{7}\)

\(\dfrac{35}{42}=\dfrac{35:7}{42:7}=\dfrac{5}{6}\)

\(\dfrac{27}{91}\left(\text{tối giản}\right)\)

\(\dfrac{115}{225}=\dfrac{115:5}{225:5}=\dfrac{23}{45}\)

Answer 3

\(\dfrac{18}{21}=\dfrac{18:3}{21:3}=\dfrac{6}{7}\\ \dfrac{35}{42}=\dfrac{35:7}{42:7}=\dfrac{5}{7}\\ \dfrac{115}{225}=\dfrac{115:5}{225:5}=\dfrac{23}{45}\)