nhanh lên

a: \(=\dfrac{3}{22}\cdot22\cdot\dfrac{3}{11}=3\cdot\dfrac{3}{11}=\dfrac{9}{11}\)

b: \(=\dfrac{5}{6}\cdot\dfrac{2}{5}=\dfrac{1}{3}\)

c: \(=\dfrac{17}{21}\left(\dfrac{3}{5}+\dfrac{2}{5}\right)=\dfrac{17}{21}\)

a : = \(\dfrac{3}{22}\). 22 . \(\dfrac{3}{11}\) = 3 . \(\dfrac{3}{11}\) = \(\dfrac{9}{11}\)

b : = \(\dfrac{5}{6}\). \(\dfrac{2}{5}\) = \(\dfrac{1}{3}\)

c: = \(\dfrac{17}{21}\)(\(\dfrac{3}{5}\) + \(\dfrac{2}{5}\)   ) = \(\dfrac{17}{21}\)

ban giai ho minh

3\22*3\11*22

=9\22*11

=9\22

11\22

=9\11

9/11 ca hai cach

=9/11

a: \(=\dfrac{3}{22}\cdot22\cdot\dfrac{3}{11}=3\cdot\dfrac{3}{11}=\dfrac{9}{11}\)

b: \(=\dfrac{5}{6}\cdot\dfrac{2}{5}=\dfrac{1}{3}\)

c: =17/21(3/5+2/5)=17/21

1) Ta có: \(\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{7}{25}\cdot\dfrac{5}{7}\right)\)

\(=\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{1}{5}\right)\)

=0

2) Ta có: \(\dfrac{8}{17}\cdot\dfrac{4}{15}+\dfrac{8}{17}\cdot\dfrac{22}{15}-\dfrac{8}{15}\cdot\dfrac{9}{17}\)

\(=\dfrac{8}{17}\left(\dfrac{4}{15}+\dfrac{22}{15}-\dfrac{9}{15}\right)\)

\(=\dfrac{8}{17}\cdot\dfrac{15}{15}=\dfrac{8}{17}\)

3) Ta có: \(\dfrac{2021}{2}\cdot\dfrac{1}{3}+\dfrac{4042}{4}\cdot\dfrac{1}{5}+\dfrac{6063}{3}\cdot\dfrac{22}{15}\)

\(=\dfrac{2021}{2}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)+2021\cdot\dfrac{22}{15}\)

\(=\dfrac{2021}{2}\cdot\dfrac{8}{15}+\dfrac{2021}{2}\cdot\dfrac{44}{15}\)

\(=\dfrac{2021}{2}\cdot\dfrac{52}{15}\)

\(=\dfrac{52546}{15}\)

4) Ta có: \(\dfrac{4}{7}\cdot\dfrac{2}{13}+\dfrac{8}{13}:\dfrac{7}{4}+\dfrac{4}{7}:\dfrac{13}{2}+\dfrac{4}{7}\cdot\dfrac{1}{13}\)

\(=\dfrac{4}{7}\left(\dfrac{2}{13}+\dfrac{8}{13}+\dfrac{2}{13}+\dfrac{1}{13}\right)\)

\(=\dfrac{4}{7}\)

1) Tính biểu thức:

3/22 x 33/11 x 22= 3/22 x22 x 3=3 x 3=9

3/5 x 17/21 + 17/21 + 2/5= 17/21(3/5 + 2/5)= 17/21x 1=17/21

(1/2+1/3)2/5=1/2x2/5+1/3x2/5 =1/5+2/15=1/3

Bài 1 : Tính bằng cách thuận tiện 

A = 3/13 x 5/7 + 2/13 x 3/7

= 2/13 + 1/13 x 5/7 + 2/13 x 3/7

=  2/13 x 72/91 + 2/13 x 3/7

= 2/13 x ( 72/91 + 3/7 )

= 2/13 x  37/24

= 37/156.

B = 21/22 x 17/8 + 21/8 x 7/22

= 21/22 x 17/8 + 17/8 + 4/8 x 7/22

=  21/22 x 17/8 + 17/8 x 7/44

=  ( 21/22 + 7/44 ) x 21/22

=  31/44 x 21/22

=  651/968.

Chúc bạn học tốt!!!

1a) \(\frac{10}{11}:\frac{11}{3}=\frac{10}{11}.\frac{3}{11}=\frac{30}{121}\)

b) \(3,42:0,75.8,4-6,8\)

\(=4,56.8,4-6,8=38,304-6,8=31,504\)

2a) \(\frac{21}{11}.\frac{22}{17}.\frac{68}{63}=\frac{21.22.68}{11.17.63}=\frac{7.3.2.11.17.4}{11.17.3.3.7}=\frac{2.4}{3}=\frac{8}{3}\)

b) \(\frac{5}{14}.\frac{7}{13}.\frac{26}{25}=\frac{5.7.26}{14.13.25}=\frac{5.7.13.2}{2.7.13.5.5}=\frac{1}{5}\)

\(\frac{10}{11}:1\frac{1}{3}\)

\(=\frac{10}{11}:\frac{4}{3}\)

\(=\frac{10}{11}\cdot\frac{3}{4}\)

\(=\frac{15}{22}\)

\(3,42:0,57\cdot8,4-6,8\)

\(=6\cdot8,4-6,8\)

\(=50,4-6,8\)

\(43,6\)

2.

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

\(=\frac{21\cdot22\cdot68}{11\cdot17\cdot63}\)

\(=\frac{21\cdot11\cdot2\cdot17\cdot4}{11\cdot17\cdot21\cdot3}\)

\(=\frac{̸21\cdot̸11\cdot2\cdot̸17\cdot4}{̸11\cdot̸17\cdot̸21\cdot3}\)

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

\(\frac{5}{14}\cdot\frac{7}{13}\cdot\frac{26}{25}\)

\(=\frac{5\cdot7\cdot26}{14\cdot13\cdot25}\)

\(=\frac{̸5\cdot̸7\cdot̸13\cdot2}{̸7\cdot2\cdot̸13\cdot̸5\cdot5}\)

\(=\frac{2}{10}\)

\(\frac{3}{22}\times\frac{3}{11}\times22\)

1.\(=\frac{3\times3\times22}{22\times11\times1}\)

\(=\frac{3\times3}{11\times1}\)

\(=\frac{9}{11}\)

2.  \(=\frac{9}{242}\times22\)

\(=\frac{198}{242}\)

\(=\frac{9\times2\times11}{2\times11\times11}\)

\(=\frac{9}{11}\)

\(\left(\frac{1}{2}+\frac{1}{3}\right)\times\frac{2}{5}\)

1.\(=\frac{5}{6}\times\frac{2}{5}\)

\(=\frac{5\times2}{3\times2\times5}\)

\(=\frac{1}{3}\)

2.\(\)\(=\frac{1}{2}\times\frac{2}{5}+\frac{1}{3}\times\frac{2}{5}\)

\(=\frac{1}{5}+\frac{2}{15}\)

\(=\frac{3}{15}+\frac{2}{15}\)

\(=\frac{5}{15}=\frac{1}{3}\)

Have a good day