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12 tháng 8 2021

f) \(-\dfrac{1}{2}+\dfrac{11}{4}-\left(\dfrac{11}{4}-\dfrac{1}{2}\right)=-\dfrac{1}{2}+\dfrac{11}{4}-\dfrac{11}{4}+\dfrac{1}{2}=0\)

g) \(\left(\dfrac{92}{9}+\dfrac{13}{5}\right)-\dfrac{47}{9}=\left(\dfrac{92}{9}-\dfrac{47}{9}\right)+\dfrac{13}{5}=5+\dfrac{13}{5}=\dfrac{25}{5}+\dfrac{13}{5}=\dfrac{38}{5}\)

h) \(\left(\dfrac{44}{7}-\dfrac{32}{9}\right)-\left(\dfrac{37}{7}+\dfrac{4}{9}\right)=\dfrac{44}{7}-\dfrac{32}{9}-\dfrac{37}{7}-\dfrac{4}{9}=\left(\dfrac{44}{7}-\dfrac{37}{7}\right)-\left(\dfrac{32}{9}+\dfrac{4}{9}\right)=1-4=-3\)

12 tháng 8 2021

f) -1/2 + 11/4 - (11/4 - 1/2)

= -1/2 + 11/4 - 11/4 + 1/2

= -1/2 + 0 + 1/2

= 0

g) (92/9 + 13/5) - 47/9

= 92/9 + 13/5 - 47/9

=(92/9 - 47/9) + 13/5

= 5 +13/5

= 5 và 13/5

h) (44/7 - 32/9) - (37/7  + 4/9)

= 44/7 - 32/9 - 37/7 - 4/9

= (44/7 - 37/7) + (32/9 - 4/9)

= 7 + 28

= 35

k cho mik nha

9 tháng 4 2018

a )  \(-\frac{3}{7}.\frac{3}{11}+-\frac{3}{7}.\frac{8}{11}+1\frac{3}{7}\)

\(=-\frac{3}{7}.\left(\frac{3}{11}+\frac{8}{11}\right)+\frac{10}{7}\)

\(=-\frac{3}{7}.\frac{11}{11}+\frac{10}{7}\)

\(=-\frac{3}{7}.1+\frac{10}{7}\)

\(=\frac{10}{7}\)

b )   \(75\%.10,5=\frac{3}{4}.10,5=7,875\)

c )  \(5-3.\left(\left|-4\right|-30:15\right)\)

\(=5-3.\left(4-2\right)\)

\(=5-3.2\)

\(=5-6\)

\(=-1\)

d )  \(-\frac{5}{7}.\frac{2}{11}+-\frac{5}{7}.\frac{9}{11}+1\frac{5}{7}\)

\(=-\frac{5}{7}.\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{12}{7}\)

\(=-\frac{5}{7}.1+\frac{12}{7}\)

\(=\frac{7}{7}\)

\(=1\)

Chúc bạn học tốt !!! 

28 tháng 2 2023

`a)3/5+(-4/9)`

`=3/5-4/9`

`=27/45-20/45`

`=7/45`

`b)3/5+2/5 . 15/8`

`=3/5 + 30/40`

`=3/5+3/4`

`=12/20+15/20`

`=27/20`

`c)7/2 . 8/13 + 8/13 . (-5/2)`

`=8/13 . (7/2 +(-5)/2)`

`=8/13 . 1`

`=8/13`

`d)-5/17 . (-9/23)+9/23 . (-22/17) + 11 9/23`

`=-5/17 . (-9/23) + 9/23 . (-1) . 22/17 + 11 + 9/23`

`=-5/17 . (-9/23) + (-9/23) . 22/17+11+9/23`

`= -9/23 ( -5/17 + 22/17)+11+9/23`

`= - 9/23 . 1+11+9/23`

`=-9/23+11+9/23`

`=(-9/23+9/23)+11`

`=0+11`

`=11`

a: =27/45-20/45=7/45

b: =3/5+30/40

=3/5+3/4

=12/20+15/20

=27/20

c: =8/13(7/2-5/2+1)=8/13*2=16/13

d: =9/23*5/17-9/23*22/17+11+9/23

=-9/23+11+9/23

=11

 

4 tháng 5 2016

\(a,\frac{-3}{4}+\frac{3}{7}+\frac{-1}{4}+\frac{4}{9}+\frac{4}{7}\)

\(=\frac{-3}{4}+\frac{-1}{4}+\frac{3}{7}+\frac{4}{7}+\frac{4}{9}\)

\(=-1+1+\frac{4}{9}\)

\(=\frac{4}{9}\)

\(b,\frac{-7}{9}\cdot\frac{4}{11}+\frac{-7}{9}\cdot\frac{7}{11}+5\frac{7}{9}\)

\(=\frac{-7}{9}\cdot\left(\frac{4}{11}+\frac{7}{11}\right)+\frac{52}{9}\)

\(=\frac{-7}{9}\cdot1+\frac{52}{9}\)

\(=\frac{-7}{9}+\frac{52}{9}=\frac{45}{9}=5\)

Ý c) bn tự làm nha. Mk ko làm đc. Nhìn nó rắc rối lắm.

Chúc bn hc tốt nha !!! TỨ DIỆP THẢO

4 tháng 6 2023

câu c bn phá ngoặc ra rồi ghép lại với nhau là xong

 

 

1 tháng 4 2015

A= \(11\frac{3}{13}-\left(2\frac{4}{7}+5\frac{3}{13}\right)\)

  = \(11\frac{3}{13}-2\frac{4}{7}-5\frac{3}{13}\)

 = \(\left(11\frac{3}{13}-5\frac{3}{13}\right)-2\frac{4}{7}\)

= \(6-2\frac{4}{7}\)

= \(3\frac{3}{7}\)

 

B= \(\left(96\frac{4}{9}+3\frac{7}{11}\right)-4\frac{4}{9}\)

  = \(96\frac{4}{9}+3\frac{7}{11}-4\frac{4}{9}\)

 =  \(\left(96\frac{4}{9}-4\frac{4}{9}\right)+3\frac{7}{11}\)

 = \(92+3\frac{7}{11}\)

 = \(95\frac{7}{11}\)

 

C= \(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+1\frac{5}{7}\)

  = \(\frac{-5}{7}.\left(\frac{2}{11}+\frac{9}{11}\right)+1\frac{5}{7}\)

  = \(\frac{-5}{7}.1+1\frac{5}{7}\)

  = \(\frac{-5}{7}+1\frac{5}{7}\)

  = 1

 

(ý D bn tự làm ha)

1 tháng 4 2015

mình  vieetts ra thì dài lám 

nếu bạn đã chác chăn về kiến thức thì hãy phân tích rồi tìm cách lam

còn ngược lại ban hãy tính máy tính rồi đoán cách làm cũng được

 

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

=-1+1-2/11

=-2/11

28 tháng 7 2023

giải thích rõ hơn đi ạ

21 tháng 4 2019

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

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

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

\(0+\frac{1}{2}+\frac{4}{5}=\frac{13}{10}\)

Nhiều quá bạn ơi

1 tháng 8 2020

a) \(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+........+\frac{1}{99.100}\)

\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+.........+\frac{1}{99}-\frac{1}{100}\)

\(=\frac{1}{2}-\frac{1}{100}=\frac{49}{100}\)

b) \(\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+..........+\frac{2}{73.75}\)

\(=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+.......+\frac{1}{73}-\frac{1}{75}\)

\(=\frac{1}{3}-\frac{1}{75}=\frac{8}{25}\)

c) \(\frac{4}{4.6}+\frac{4}{6.8}+\frac{4}{8.10}+..........+\frac{4}{64.66}\)

\(=2.\left(\frac{2}{4.6}+\frac{2}{6.8}+\frac{2}{8.10}+..........+\frac{2}{64.66}\right)\)

\(=2.\left(\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+\frac{1}{8}-\frac{1}{10}+.....+\frac{1}{64}-\frac{1}{66}\right)\)

\(=2.\left(\frac{1}{4}-\frac{1}{66}\right)=2.\frac{31}{132}=\frac{31}{66}\)

1 tháng 8 2020

d) \(\frac{9}{5.8}+\frac{9}{8.11}+\frac{9}{11.14}+........+\frac{9}{497.500}\)

\(=3.\left(\frac{3}{5.8}+\frac{3}{8.11}+\frac{3}{11.14}+..........+\frac{3}{497.500}\right)\)

\(=3.\left(\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}+......+\frac{1}{497}-\frac{1}{500}\right)\)

\(=3.\left(\frac{1}{5}-\frac{1}{500}\right)=3.\frac{99}{500}=\frac{297}{500}\)

e) \(\frac{1}{5.7}+\frac{1}{7.9}+\frac{1}{9.11}+......+\frac{1}{93.95}\)

\(=\frac{1}{2}.\left(\frac{2}{5.7}+\frac{2}{7.9}+\frac{2}{9.11}+........+\frac{2}{93.95}\right)\)

\(=\frac{1}{2}.\left(\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}+........+\frac{1}{93}-\frac{1}{95}\right)\)

\(=\frac{1}{2}.\left(\frac{1}{5}-\frac{1}{95}\right)=\frac{1}{2}.\frac{18}{95}=\frac{9}{95}\)

g) \(\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+..........+\frac{1}{200.203}\)

\(=\frac{1}{3}.\left(\frac{3}{2.5}+\frac{3}{5.8}+\frac{3}{8.11}+........+\frac{3}{200.203}\right)\)

\(=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+......+\frac{1}{200}-\frac{1}{203}\right)\)

\(=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{203}\right)=\frac{1}{3}.\frac{201}{406}=\frac{67}{406}\)