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21 tháng 6

\(\dfrac{9}{5}+\dfrac{5}{8}=\dfrac{72}{40}+\dfrac{25}{40}=\dfrac{97}{40}\)

\(\dfrac{3}{5}+\dfrac{13}{9}=\dfrac{27}{45}+\dfrac{65}{45}=\dfrac{82}{45}\)

\(\dfrac{2}{3}+\dfrac{11}{2}=\dfrac{4}{6}+\dfrac{33}{6}=\dfrac{37}{6}\)

\(\dfrac{9}{4}+\dfrac{17}{20}=\dfrac{45}{20}+\dfrac{17}{20}=\dfrac{62}{20}=\dfrac{31}{10}\)

\(\dfrac{43}{6}+\dfrac{45}{8}=\dfrac{172}{24}+\dfrac{135}{24}=\dfrac{307}{24}\)

\(\dfrac{5}{9}+\dfrac{7}{15}=\dfrac{25}{45}+\dfrac{21}{45}=\dfrac{46}{45}\)

21 tháng 6

\(\dfrac{9}{5}+\dfrac{5}{8}\\ =\dfrac{72}{40}+\dfrac{25}{40}\\ =\dfrac{97}{40}\\ ----------\\ \dfrac{3}{5}+\dfrac{13}{9}\\ =\dfrac{27}{45}+\dfrac{65}{45}\\ =\dfrac{92}{45}\\ --------\\ \dfrac{2}{3}+\dfrac{11}{2}\\ =\dfrac{4}{6}+\dfrac{33}{6}\\ =\dfrac{37}{6}\\ --------\\ \dfrac{9}{4}+\dfrac{17}{20}\\ =\dfrac{45}{20}+\dfrac{17}{20}\\ =\dfrac{62}{20}=\dfrac{31}{10}\\ ----------\\ \dfrac{43}{6}+\dfrac{45}{8}\\ =\dfrac{172}{24}+\dfrac{135}{24}\\ =\dfrac{307}{24}\)

\(-----------\\ \dfrac{5}{9}+\dfrac{7}{15}\\ =\dfrac{25}{45}+\dfrac{21}{45}\\ =\dfrac{46}{45}\)

3 tháng 3 2023

`4/7+4`

`=4/7+4/1`

`=4/7+28/7`

`=32/7`

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`3+6/11`

`=33/11+6/11`

`=39/11`

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`3-5/7`

`=3/1-5/7`

`=21/7-5/7`

`=16/7`

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`21/9-2`

`=21/9-18/9`

`=3/9`

`=1/3`

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`15/24+2`

`=15/24+48/24`

`=63/24`

`=21/16`

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`63/45-20/25`

`=63/45-4/5`

`=63/45-36/45`

`=27/45`

`=9/15`

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`3/4-2/8`

`=3/4-1/4`

`=2/4`

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`6/7-5/8`

`=48/56-35/56`

`=13/56`

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`37/45-5/9`

`=37/45-25/45`

`=12/45`

`=4/15`

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`46/39-11/13`

`=46/39-33/39`

`=13/39`

`=1/2`

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`5/12+3/4+1/3`

`=5/12+9/12+4/12`

`=14/12+4/12`

`=18/12`

`=3/2`

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`1/2+3/7+11/14`

`=7/14+6/14+11/14`

`=13/14+11/14`

`=24/14`

`=12/7`

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`7/10-(1/5+1/4)`

`=7/10-(4/20+5/20)`

`=7/10-9/20`

`=14/20-9/20`

`=5/20`

`=1/4`

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`15/4-2/3-3/4`

`=(15/4-3/4)-2/3`

`=12/4-2/3`

`=3-2/3`

`=9/3-2/3`

`=7/3`

30 tháng 4 2016

1) x - 2 = -6

x = - 6 + 2

x = -4

2) -5x-(-3)=13

-5x+3=13

-5x=13-3=10

x=10:(-5)

x=-2

3) 15-(x-7)=21

15-x+7=21

15-x=21-7=14

x=15-14=1

4) 3x+17=2

3x=2-17=-15

x=-15:3=-5

5) 45-(x-9)=-35

45-x+9=-35

45-x=-35-9=-44

x=45-(-44)=89

6) -5+x=15

x=15-(-5)

x=20

7) 2x-(-17)=15

2x+17=15

2x=15-17=-2

x=-2:2=-1

 

30 tháng 4 2016

ai giúp mk câu này với

a: =-1+17/20=-3/20

b: =(28/60-33/60)*(-25/3)

=(-1/12)*(-25/3)=1/12*25/3=25/36

c: \(=\dfrac{1}{3}\cdot\dfrac{1}{3}=\dfrac{1}{9}\)

 

a: =35/17-18/17-9/5+4/5

=1-1=0

b: =-7/19(3/17+8/11-1)

=7/19*18/187=126/3553

c: =26/15-11/15-17/3-6/13

=1-6/13-17/3

=7/13-17/3=-200/39

a) Ta có: \(\dfrac{-5}{7}\left(\dfrac{14}{5}-\dfrac{7}{10}\right):\left|-\dfrac{2}{3}\right|-\dfrac{3}{4}\left(\dfrac{8}{9}+\dfrac{16}{3}\right)+\dfrac{10}{3}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)\)

\(=\dfrac{-5}{7}\cdot\dfrac{3}{2}\cdot\dfrac{21}{10}-\dfrac{3}{4}\cdot\dfrac{56}{3}+\dfrac{10}{3}\cdot\dfrac{8}{15}\)

\(=\dfrac{-9}{4}-14+\dfrac{16}{9}\)

\(=\dfrac{-1621}{126}\)

b) Ta có: \(\dfrac{17}{-26}\cdot\left(\dfrac{1}{6}-\dfrac{5}{3}\right):\dfrac{17}{13}-\dfrac{20}{3}\left(\dfrac{2}{5}-\dfrac{1}{4}\right)+\dfrac{2}{3}\left(\dfrac{6}{5}-\dfrac{9}{2}\right)\)

\(=\dfrac{-17}{26}\cdot\dfrac{13}{17}\cdot\dfrac{-3}{2}-\dfrac{20}{3}\cdot\dfrac{3}{20}+\dfrac{2}{3}\cdot\dfrac{-33}{10}\)

\(=\dfrac{3}{4}-1-\dfrac{11}{5}\)

\(=-\dfrac{49}{20}\)

a: =-5/9-4/9+8/15+7/15-2/11=-2/11

b: =10/17+7/17-5/13-8/13+11/25

=11/25

c: =(9/12-2/12)*3/2=7/12*3/2=21/24=7/8

d: =(31/10-25/10)*3-2

=3/5*3-2

=9/5-2

=-1/5

9 tháng 9 2016

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10=55

2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20=110

1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19=100

k mk nha pạn hiền!

9 tháng 9 2016

10 +1 = 11 có 10 số vậy thì 10 : 2 = 5 thì sẽ bằng 5x11 = 55

2 + 20 = 22 cũng có 10 số lấy 10 : 2 = 5 se bang 22 x5 = 110

1+19 = 20 , 10 : 2 = 5 , 20x5 = 100

16 tháng 10 2023

`1/3-5/6+3/2`

`=2/6-5/6+9/6`

`=-3/6+9/6`

`=6/6`

`=1`

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`2/13-(15/13+4-0,5)`

`=2/13-1513-4+0,5`

`=(2/13-15/13)-4,5`

`=-13/13-4,5`

`=-1-4,5`

`=-5,5`

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`-(1/9+7/5-3/11)+(-2/5+17/9-8/11)`

`=-1/9-7/5+3/11+(-2)/5+17/9-8/11`

`=(-1/9+17/9)+(-7/5+(-2)/5)+(3/11-8/11)`

`=16/9-9/5-5/11`

`=-236/495`

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`5,75-3,25+5 5/6`

`=5/2+35/6`

`=15/6+35/6`

`=50/6`

`=25/3`