Tính bằng cách thuận tiện: 4/5 x 3/7 + 4/5 x 6/7 - 4/5 x 4/14

\(\frac{4}{5}\times\frac{3}{7}+\frac{4}{5}\times\frac{6}{7}-\frac{4}{5}\times\frac{4}{14}\)

\(=\frac{4}{5}\times\left(\frac{3}{7}+\frac{6}{7}-\frac{4}{14}\right)\)

\(=\frac{4}{5}\times\left(\frac{6}{14}+\frac{12}{14}-\frac{4}{14}\right)\)

\(=\frac{4}{5}\times\frac{14}{14}\)

\(=\frac{4}{5}\times1=\frac{4}{5}\)

4/5 x 3/7 + 4/5 x 6/7 - 4/5 x 4/14

= 4/5 x (3/7 + 6/7 - 4/14)

= 4/5 x (6/14 + 12/14 - 4/14)

= 4/5 x 14/14

= 4/5 x 1 = 4/5

4/5 x 3/7 + 4/5 x 6/7 - 4/5 x 4/14

= 4/5 x (3/7 + 6/7 - 4/14)

= 4/5 x (9/7 - 2/7)

= 4/5 x 7/7

= 4/5 x 1 = 4/5