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21 tháng 4 2024

\(\dfrac{1}{4}:5+\dfrac{1}{3}\times\dfrac{1}{4}\)

\(=\dfrac{1}{4}\times\dfrac{1}{5}+\dfrac{1}{3}\times\dfrac{1}{4}\)

\(=\dfrac{1}{4}\times\left(\dfrac{1}{5}+\dfrac{1}{3}\right)\)

\(=\dfrac{1}{4}\times\left(\dfrac{3}{15}+\dfrac{5}{15}\right)\)

\(=\dfrac{1}{4}\times\dfrac{8}{15}\)

\(=\dfrac{2}{15}\)

`#NqHahh`

21 tháng 4 2024

  1/4 : 5 + 1/3 . 1/4

= 1/20 + 1/12

= 2/15.

5 tháng 3 2018

22/7

7/5

43/4

15/28

1/42

7/12

1/4

2/5

5/12

7 tháng 6 2016

\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)\)\(\frac{2-1}{2}.\frac{3-1}{3}.\frac{4-1}{4}\)\(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}\)\(\frac{1.2.3}{2.3.4}=\frac{1}{4}\)

\(\left(1+\frac{1}{2}\right):\left(1+\frac{1}{3}\right):\left(1+\frac{1}{4}\right)\)\(\frac{2+1}{2}:\frac{3+1}{3}:\frac{4+1}{4}\)\(\frac{3}{2}:\frac{4}{3}:\frac{5}{4}=\frac{3}{2}.\frac{3}{4}.\frac{4}{5}=\frac{3.3.4}{2.4.5}=\frac{3.3}{2.5}=\frac{9}{10}\)

\(\frac{6}{5}-\frac{4}{5}.\frac{4}{8}+1=\frac{6}{5}+1-\frac{4.4}{5.8}=\frac{6+5}{5}-\frac{4}{5.2}=\frac{11}{5}-\frac{2}{5}=\frac{9}{5}\)
x < \(\frac{3}{4}+\frac{4}{5}=\frac{15}{20}+\frac{16}{20}=\frac{31}{20}=\frac{20}{20}+\frac{11}{20}=1\frac{11}{20}\)=> x = 0 ; 1

\(\frac{1}{2}+\frac{2}{3}< x< 4-\frac{5}{4}\)<=> \(\frac{3}{6}+\frac{4}{6}< x< \frac{16}{4}-\frac{5}{4}\)<=> \(\frac{7}{6}< x< \frac{11}{4}\)=> \(\frac{14}{12}< \frac{12x}{12}< \frac{33}{12}\)

=> 14 < 12x < 33 => 12x = 24 => x = 24 : 12 = 2

2 tháng 5 2016

Bài 1

1/2 x 3/4 : 4/5 

= 3/8 : 4/5 

= 3/8 x 5/4

= 15/32

2/3 + 1/6 - 1/2

= 4/6 + 1/6 - 3/6

= 5/6 - 3/6

= 1/3

3/5 + 4 : 2/3 - 3/2

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

= 3/5 + 6 - 3/2

= 3/5 + 30/5 - 3/2

= 33/5 - 3/2

= 66/10 - 15/10

= 28/5

Bài 2

x - 1/4 = 1/2 

x         = 1/2 + 1/4

x         = 2/4 + 1/4 

x         = 3/4

2/3 + x = 1

         x = 1 - 2/3 

         x = 3/3 - 2/3

         x = 1/3

2 tháng 5 2016

1/2 x 3/4 : 4/5

=1/2 x 3/4 x 4/5

=3/8 x 4/5

=3/10

23 tháng 1 2020

                                                                Bài giải

a, \(\frac{4}{5}-\frac{2}{3}+\frac{1}{5}-\frac{1}{3}\)

\(=\left(\frac{4}{5}+\frac{1}{5}\right)-\left(\frac{2}{3}+\frac{1}{3}\right)=1-1=0\)

b, \(\frac{2}{5}\text{ x }\frac{7}{4}-\frac{2}{5}\text{ x }\frac{3}{7}\)

\(=\frac{2}{5}\text{ x }\left(\frac{7}{4}-\frac{3}{7}\right)=\frac{2}{5}\text{ x }\frac{37}{28}=\frac{37}{70}\)

c, \(\frac{13}{4}\text{ x }\frac{2}{3}\text{ x }\frac{4}{13}\text{ x }\frac{3}{12}=\frac{13\text{ x }2\text{ x }4\text{ x }3}{4\text{ x }3\text{ x }13\text{ x }12}=\frac{1}{6}\)

d,  \(\frac{75}{100}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\frac{3}{4}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{18}{21}+\frac{3}{21}\right)+\left(\frac{19}{32}+\frac{13}{32}\right)\)

\(=1+1+1\)

\(=3\)

e, \(\frac{2}{5}+\frac{6}{9}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{2}{5}+\frac{2}{3}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{1}{5}\left(2+3\right)+\frac{1}{3}\left(2+1\right)+\frac{1}{4}\left(3+1\right)\)

\(=\frac{1}{5}\cdot5+\frac{1}{3}\cdot3+\frac{1}{4}\cdot4\)

\(=1+1+1\)

\(=3\)

23 tháng 1 2020

a, \(\frac{4}{5}-\frac{2}{3}+\frac{1}{5}-\frac{1}{3}\)

\(=\left(\frac{4}{5}+\frac{1}{5}\right)-\left(\frac{2}{3}+\frac{1}{3}\right)=1-1=0\)

b, \(\frac{2}{5}\text{ x }\frac{7}{4}-\frac{2}{5}\text{ x }\frac{3}{7}\)

\(=\frac{2}{5}\text{ x }\left(\frac{7}{4}-\frac{3}{7}\right)=\frac{2}{5}\text{ x }\frac{37}{28}=\frac{37}{70}\)

c, \(\frac{13}{4}\text{ x }\frac{2}{3}\text{ x }\frac{4}{13}\text{ x }\frac{3}{12}=\frac{13\text{ x }2\text{ x }4\text{ x }3}{4\text{ x }3\text{ x }13\text{ x }12}=\frac{1}{6}\)

d,  \(\frac{75}{100}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\frac{3}{4}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{18}{21}+\frac{3}{21}\right)+\left(\frac{19}{32}+\frac{13}{32}\right)\)

\(=1+1+1\)

\(=3\)

e, \(\frac{2}{5}+\frac{6}{9}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{2}{5}+\frac{2}{3}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{1}{5}\left(2+3\right)+\frac{1}{3}\left(2+1\right)+\frac{1}{4}\left(3+1\right)\)

\(=\frac{1}{5}\cdot5+\frac{1}{3}\cdot3+\frac{1}{4}\cdot4\)

\(=1+1+1\)

\(=3\)

14 tháng 4 2017

Gửi kết bn với mh nhé!

14 tháng 4 2017

ban ko tra loi ho minh cau nay a 

neu the minh ket ban kieu gi

2 tháng 5 2016

sory tớ bị đau tay không viết được nhiều !

16 tháng 8 2016

\(\frac{2}{3}\cdot\frac{3}{4}\cdot\frac{4}{5}:\frac{1}{5}\)


\(=\frac{1}{2}\cdot4\)

\(=2\)

\(\frac{1\cdot2\cdot3\cdot4}{5\cdot6\cdot7\cdot8}=\frac{1\cdot1\cdot3\cdot1}{5\cdot3\cdot7\cdot2}=\frac{1\cdot1\cdot1\cdot1}{5\cdot1\cdot7\cdot2}=\frac{1}{70}\)

\(\frac{2}{5}\cdot\frac{3}{4}\cdot\frac{5}{6}:\frac{3}{4}\)

\(=\frac{2}{5}\cdot\frac{5}{6}\cdot\frac{3}{4}:\frac{3}{4}\)

\(=\frac{1}{3}\cdot1\)

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

16 tháng 8 2016

\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}\div\frac{5}{1}\)

\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}\times\frac{5}{1}\)

\(=\frac{2}{1}=2\)

Các phần khác tương tự nhé em , nếu ko biết giải qua tin nhắn chị gửi cho

25 tháng 2 2020

1/2+4/3*1/6

=1/2+4/18

=13/18

25 tháng 2 2020

1/2 + 4/3 = 3/6 + 8/6 = 11/6

4/5 + 3/4 : 2/3 = 4/5 + 3/4 * 3/2 = 4/5 + 9/8 = 32/40 + 45/40 = 77/40

7/2 - 4/3 * 1/6 = 7/2 - 2/9 = 63/18 - 4/18 = 59/18

4/5 * 4/7 : 2/3 = 16/35 : 2/3 = 16/35 * 3/2 = 24/35

1/4 : 5/3 + 1/6 = 1/4 * 3/5 + 1/6 = 3/20 + 1/6 = 9/60 + 10/60 = 19/60

3 - 4/5 : 1/3 = 3 - 4/5 * 3/1 = 3 - 12/5 = 15/5 - 12/5 = 3/5

5/9 * 2/7 - 3/7 = 10/63 - 3/7 = 10/63 - 27/63 = -17/63  

\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}:\frac{1}{5}\)

\(=\frac{1}{2}\times\frac{4}{5}:\frac{1}{5}\)

\(=\frac{2}{5}:\frac{1}{5}\)

\(=2\)

16 tháng 8 2016

a) 2/3 x 3/4 x 4/5 : 1/5

= 1/2 x 4

= 2

b) 1 x 2 x 3 x 4/5 x 6 x 7 x 8

= 2 x 3 x 24/5 x 56

= 6 x 72/5 x 56

= 432/5 x 56

= 24192/5

c) 2/5 x 3/4 x 5/6 : 3/4

= 3/10 x 10/9

= 1/3

x +\(\frac{1}{6}\)=\(\frac{1}{3}\)-\(\frac{1}{4}\)

x +\(\frac{1}{6}\)=\(\frac{1}{12}\)

x            =\(\frac{1}{12}\)-\(\frac{1}{6}\)

x            =\(-\frac{1}{12}\)

x -\(\frac{5}{12}\)=\(\frac{1}{3}+\frac{1}{4}\)

x -\(\frac{5}{12}\)=\(\frac{7}{12}\)

x             =\(\frac{7}{12}\)+\(\frac{5}{12}\)

x             = 1

x +\(\frac{1}{2}\)=\(\frac{4}{5}\)

x             =\(\frac{4}{5}\)-\(\frac{1}{2}\)

x             =\(\frac{3}{10}\)

x -\(\frac{1}{6}\)=\(\frac{1}{2}\)+\(\frac{1}{3}\)

x -\(\frac{1}{6}\)=\(\frac{5}{6}\)

x            =\(\frac{5}{6}\)+\(\frac{1}{6}\)

x            = 1

x +\(\frac{1}{8}\)=\(\frac{1}{2}\)-\(\frac{1}{3}\)

x +\(\frac{1}{8}\)=\(\frac{1}{6}\)

x             =\(\frac{1}{6}\)-\(\frac{1}{8}\)

x             =\(\frac{1}{24}\)

Học tốt!!!