Question

thực hiện phép nhân sau

Answer 1

a: \(\dfrac{3}{7}\cdot\dfrac{14}{5}=\dfrac{3}{5}\cdot\dfrac{14}{7}=\dfrac{3}{5}\cdot2=\dfrac{6}{5}\)

b: \(\dfrac{35}{9}\cdot\dfrac{81}{7}=\dfrac{81}{9}\cdot\dfrac{35}{7}=5\cdot9=45\)

c: \(\dfrac{28}{17}\cdot\dfrac{68}{14}=\dfrac{68}{17}\cdot\dfrac{28}{14}=4\cdot2=8\)

d: \(\dfrac{35}{46}\cdot\dfrac{23}{105}=\dfrac{35}{105}\cdot\dfrac{23}{46}=\dfrac{1}{2}\cdot\dfrac{1}{3}=\dfrac{1}{6}\)

e: \(\dfrac{12}{5}\cdot\dfrac{10}{18}=\dfrac{12}{18}\cdot\dfrac{10}{5}=\dfrac{2}{3}\cdot2=\dfrac{4}{3}\)

f: \(\dfrac{15}{4}\cdot\dfrac{8}{10}=\dfrac{15}{10}\cdot\dfrac{8}{4}=\dfrac{3}{2}\cdot2=3\)

Answer 2

a) \(\dfrac{3}{7}\cdot\dfrac{14}{5}=\dfrac{3\cdot14}{7\cdot5}=\dfrac{3\cdot2}{5}=\dfrac{6}{5}\)

b) \(\dfrac{35}{9}\cdot\dfrac{81}{7}=\dfrac{35\cdot81}{9\cdot7}=5\cdot9=45\)

c) \(\dfrac{28}{17}\cdot\dfrac{68}{14}=\dfrac{28\cdot68}{17\cdot14}=2\cdot4=8\)

d) \(\dfrac{35}{46}\cdot\dfrac{23}{105}=\dfrac{35}{105}\cdot\dfrac{23}{46}=\dfrac{1}{3}\cdot\dfrac{1}{2}=\dfrac{1}{6}\) 

e) \(\dfrac{12}{5}\cdot\dfrac{10}{18}=\dfrac{12}{5}\cdot\dfrac{5}{9}=\dfrac{12}{9}=\dfrac{4}{3}\)

f) \(\dfrac{15}{4}\cdot\dfrac{8}{10}=\dfrac{15\cdot8}{4\cdot10}=\dfrac{3\cdot2}{2}=3\)