tại sao: 21/11 x 22/17 x 68/63 = 42/17 x 68/63 = 8/3
tại sao: 21/11 x 22/17 x 68/63 = 42/17 x 68/63 = 8/3
21/11 x 22/17 x 68/63 : 4/3
\(\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{68}{63}:\dfrac{4}{3}=\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{68}{63}\times\dfrac{3}{4}=\dfrac{462}{187}\times\dfrac{204}{252}=\dfrac{42}{17}\times\dfrac{17}{21}=\dfrac{2}{1}=2\)
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
\(=\dfrac{21}{11}\times\dfrac{22}{17}\times\dfrac{68}{63}\times\dfrac{3}{4}=\dfrac{42}{17}\times\dfrac{17}{21}=\dfrac{42}{21}=\dfrac{2}{1}=2\)
tính nhanh : 21/11 x 22/17 x 68/63
\(\frac{21}{11}.\frac{22}{17}.\frac{68}{63}\)
\(=\frac{42}{17}.\frac{68}{63}\)
\(=\frac{8}{3}\)
Tính bằng cách thuận tiện
\(^{\dfrac{21}{11}}\) x \(\dfrac{22}{17}\) x \(\dfrac{68}{63}\)
21/11 × 22/17 × 68/63
= (21 × 2 × 4)/63
= 8/3
21/11 x 22/17 x 68/63
5/14 x 7/13 x 26/25
\(\frac{21}{11}\cdot\frac{22}{17}\cdot\frac{68}{63}=\frac{21\cdot22\cdot68}{11\cdot17\cdot63}\)=\(\frac{1\cdot2\cdot4}{1\cdot1\cdot3}=\frac{8}{3}\)
\(\frac{5}{14}\cdot\frac{7}{13}\cdot\frac{26}{25}=\frac{5\cdot7\cdot26}{14\cdot43\cdot25}\)=\(\frac{1\cdot1\cdot2}{2\cdot1\cdot5}\)\(=\frac{2}{10}=\frac{1}{5}\)
a] 21/11 x 22/17 x 68/63=
b] 5/14 x 7/13x 26/25=
a) 21/11*22/17*68/63 =8/3
b)5/14*7/13*26/25 =1/5
Tính bằng cách thuận tiện nhất
21/11 x 22 /17 x 68/63
5/14x7/13x6/25
21/11 x 22/17 x 68/63 = 952/357
5/14 x 7/13 x 6/25=3/65
\(\frac{21}{11}X\frac{22}{17}X\frac{68}{63}=\frac{952}{357} \)
\(\frac{5}{14}X\frac{7}{13}X\frac{6}{25}=\frac{3}{65}\)
bài tính nhanh : 21/22 x 44/17 x 68/63
tính bằng cách thuận tiện
21/11 x 22/17 x 68/63
5/14 x 7/13 x 26/25
cái này là 2 phép tính riêng biệt hay là gì hả bạn ?