\(\frac{1}{7}\cdot\frac{2}{3}+\frac{5}{6}:\frac{3}{10}-\frac{2}{3}\cdot\frac{3}{7}\)

\(=\left(\frac{1}{7}\cdot\frac{2}{3}-\frac{2}{3}\cdot\frac{3}{7}\right)+\frac{5}{6}\cdot\frac{10}{3}\)

\(=\frac{2}{3}\cdot\left(-\frac{2}{7}\right)+\frac{5}{3}\cdot\frac{5}{3}\)

\(=-\frac{4}{21}+\frac{25}{6}=\frac{167}{42}\)

Xin lỗi không nhanh được 

Bạn ơi câu này trả lời r mà

=7/10(3+5+2)

=7/10*10

=7

3 x 7/10 + 7/10 x 5 + 2 x 7/10

= 7/10 x (3 + 5 + 2)

= 7/10 x 10

= 7

\(3\times\dfrac{7}{10}+\dfrac{7}{10}\times5+2\times\dfrac{7}{10}\)

\(=\dfrac{7}{10}\times\left(3+5+2\right)\)

\(=\dfrac{7}{10}\times10\)

\(=7\)

\(\dfrac{7}{10}\times\left(3+5+2\right)=\dfrac{7}{10}\times10=\dfrac{70}{10}=7\)

`3xx7/10+7/10xx5+2xx7/10`

`=7/10xx(3+5+2)`

`=7/10xx10`

`=7`

lx

Uả cái j zị

ảnh đâu 

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

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

= 4/5 x 7/7

= 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 1

= 4/5

4/5

`4/5 xx 3/7 + 4/5 xx 6/7 - 4/5 xx 4/14`

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

`= 4/5 xx 1`

`= 4/5`

3 x 7/10 + 7/10 x 5 + 2 x 14/20

=3x7/10+7/10x5+2x7/10

=7/10x(3+5+2)

=7/10x10

=7

ta có

\(3\cdot\frac{7}{10}+\frac{7}{10}\cdot5+2\cdot\frac{14}{20}\)

\(=3\cdot\frac{7}{10}+\frac{7}{10}\cdot5+2\cdot\frac{7}{10}\)

\(=\frac{7}{10}\cdot\left(3+5+2\right)\)

\(=\frac{7}{10}\cdot10\)

\(=\frac{70}{10}=7\)

chúc bạn hok tốt!

   3x7/10+7/10x5+2x14/20

=3x7/10+7/10x5+2x7/10

=7/10x(3+5+2)

=7/10x     10

=70/10

=7

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

`3 xx 7/10 + 7/10 xx 5 + 14/10`

`= 3 xx 7/10 + 7/10 xx 5 + 7/10 xx 2`

`= 7/10 xx ( 3 + 5 + 2 )`

`= 7/10 xx 10`

`= 70/10 = 7`

_HT_

(7/10+7/10+14/10) x 15 = 28/10 = 14/5 rút gọn

                                                   =14/5 x 15

                                                   = 14/5

chúc bn học tốt nha !!!