\(\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{68}{63}\) = \(\dfrac{42}{17}\times\dfrac{68}{63}\) = \(\dfrac{8}{3}\)

 Vì \(\dfrac{21}{11}\times\dfrac{22}{17}=\dfrac{21\times22}{11\times17}=\dfrac{42}{17}\)

 Vậy:

 \(\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{63}{68}\) =\(\dfrac{42}{17}\times\dfrac{68}{63}\) =\(\dfrac{21\times2\times17\times4}{17\times21\times3}\) =\(\dfrac{8}{3}\) = 

\(\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{68}{63}:\dfrac{4}{3}=\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{68}{63}\times\dfrac{3}{4}=\dfrac{462}{187}\times\dfrac{204}{252}=\dfrac{42}{17}\times\dfrac{17}{21}=\dfrac{2}{1}=2\)

21/11 x 22/17 x 68/63 : 4/3

=( 21/11 x 22/17) x (68/63 : 4/3)

=       42/17          x        17/21

=          2/1 = 2

\(=\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{68}{63}\times\dfrac{3}{4}=\dfrac{42}{17}\times\dfrac{17}{21}=\dfrac{42}{21}=\dfrac{2}{1}=2\)

\(\frac{21}{11}.\frac{22}{17}.\frac{68}{63}\)

\(=\frac{42}{17}.\frac{68}{63}\)

\(=\frac{8}{3}\)

21/11*22/17*68/63=42/17*68/63=8/3

21/11 × 22/17 × 68/63

= (21 × 2 × 4)/63

= 8/3

\(\frac{21}{11}\cdot\frac{22}{17}\cdot\frac{68}{63}=\frac{21\cdot22\cdot68}{11\cdot17\cdot63}\)=\(\frac{1\cdot2\cdot4}{1\cdot1\cdot3}=\frac{8}{3}\)

\(\frac{5}{14}\cdot\frac{7}{13}\cdot\frac{26}{25}=\frac{5\cdot7\cdot26}{14\cdot43\cdot25}\)=\(\frac{1\cdot1\cdot2}{2\cdot1\cdot5}\)\(=\frac{2}{10}=\frac{1}{5}\)

a.= 8/3

b.= 1/5 

kb nha !~!

A=(...........)

B=(...........)

a) 21/11*22/17*68/63 =8/3

b)5/14*7/13*26/25 =1/5

21/11 x 22/17 x 68/63 = 952/357

5/14 x 7/13 x 6/25=3/65

\(\frac{21}{11}X\frac{22}{17}X\frac{68}{63}=\frac{952}{357} \)

\(\frac{5}{14}X\frac{7}{13}X\frac{6}{25}=\frac{3}{65}\)

ko iểu

8/3 nha bạn

cái này là 2 phép tính riêng biệt hay là gì hả bạn ?

2 phép tính khác nhau!