Question

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

 

 

Answer 1

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

\(=\dfrac{4}{5}\times\left(\dfrac{3}{7}+\dfrac{6}{7}-\dfrac{4}{14}\right)=\dfrac{4}{5}\times1=\dfrac{4}{5}\)

Answer 2

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 1

= 4/5

Answer 3

   \(\dfrac{4}{5}\) x \(\dfrac{3}{7}\) + \(\dfrac{4}{5}\) x \(\dfrac{6}{7}\) - \(\dfrac{4}{5}\) x \(\dfrac{4}{14}\)

= \(\dfrac{4}{5}\) x \(\dfrac{3}{7}\) + \(\dfrac{4}{5}\) x \(\dfrac{6}{7}\) - \(\dfrac{4}{5}\) x \(\dfrac{2}{7}\)

= \(\dfrac{4}{5}\) x (\(\dfrac{3}{7}\) + \(\dfrac{6}{7}\) - \(\dfrac{2}{7}\))

= \(\dfrac{4}{5}\) x 1

= \(\dfrac{4}{5}\)

 

Answer 4

\(\dfrac{4}{5}\times\dfrac{3}{7}+\dfrac{4}{5}\times\dfrac{6}{7}-\dfrac{4}{5}\times\dfrac{4}{14}\)
\(=\dfrac{4}{5}\times\dfrac{3}{7}+\dfrac{4}{5}\times\dfrac{6}{7}-\dfrac{4}{5}\times\dfrac{2}{7}\)
\(=\dfrac{4}{5}\times\left(\dfrac{3}{7}+\dfrac{6}{7}-\dfrac{2}{7}\right)\)

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

Answer 5

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

= 4/5 x 3/7 + 4/5 x 6/7 - 4/5 x 2/7

= 4/5 x (3/7 + 6/7 - 2/7)

=4/5 x 1

=4/5