Các bạn ơi giúp mình vs T-T 1) A = \(\dfrac{15}{24} \dfrac{7}{21} \dfrac{9}{34}-1\dfrac{15}{17} \dfrac{2}{3}\) 2) B = \(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)-28\dfrac{2}{7}:\left(-\dfrac{3}{5}\...

DY

ĐInh Yến Dung

26 tháng 11 2017

Các bạn ơi giúp mình vs T-T 1) A = \(\dfrac{15}{24}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\) 2) B = \(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)-28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\) 3) C = \(25.\left(-\dfrac{1}{3}\right)^3+\dfrac{1}{5}-2.\left(-\dfrac{1}{2}\right)^2-\dfrac{1}{2}\) 4) D = \(\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\) 5) E =...

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#Toán lớp 7

0

K

Kfkfj

9 tháng 12 2017

tính: A = \(\dfrac{15}{34}+\dfrac{27}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

B = \(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)-28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\)

#Toán lớp 7

1

TN

Trần Nguyễn Bảo Quyên

9 tháng 12 2017

\(A=\dfrac{15}{34}+\dfrac{27}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

\(A=\left(\dfrac{15}{34}+\dfrac{9}{34}-1\dfrac{15}{17}\right)+\left(\dfrac{27}{21}+\dfrac{2}{3}\right)\)

\(A=\left(\dfrac{15}{34}+\dfrac{9}{34}-\dfrac{32}{17}\right)+\left(\dfrac{27}{21}+\dfrac{2}{3}\right)\)

\(A=\left(\dfrac{15}{34}+\dfrac{9}{34}-\dfrac{64}{34}\right)+\left(\dfrac{27}{21}+\dfrac{14}{21}\right)\)

\(A=\dfrac{-20}{17}+\dfrac{41}{21}\)

\(A=\dfrac{-420}{357}+\dfrac{697}{357}=\dfrac{277}{357}\)

\(B=16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)-28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\)

\(B=16\dfrac{2}{7}.\left(-\dfrac{5}{3}\right)-28\dfrac{2}{7}.\left(-\dfrac{5}{3}\right)\)

\(B=\left(-\dfrac{5}{3}\right)\left(16\dfrac{2}{7}-28\dfrac{2}{7}\right)\)

\(B=\left(-\dfrac{5}{3}\right)\left(-12\right)\)

\(B=20\)

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K

Kfkfj

9 tháng 12 2017

cảm ơn nhưng câu A bạn sai rồi

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NC

Nguyễn Châu Mỹ Linh

11 tháng 11 2018

Tinh:

a) \(\dfrac{15}{24}+\dfrac{7}{21}+\dfrac{19}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

b) \(\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)

c) \(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)+28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\)

#Toán lớp 7

1

NL

Nguyễn Lê Phước Thịnh

19 tháng 11 2022

a: \(=\left(\dfrac{15}{34}+\dfrac{19}{34}\right)+\left(\dfrac{7}{21}+\dfrac{2}{3}\right)-\dfrac{32}{17}=2-\dfrac{32}{17}=\dfrac{2}{17}\)

b: \(=-8\cdot\dfrac{1}{4}:\left(\dfrac{9}{4}-\dfrac{7}{6}\right)=-2:\dfrac{27-14}{12}=\dfrac{-2\cdot12}{13}=-\dfrac{24}{13}\)

c: \(=\dfrac{-5}{3}\left(16+\dfrac{2}{7}+28+\dfrac{2}{7}\right)=\dfrac{-5}{3}\cdot\left(44+\dfrac{4}{7}\right)\)

=-520/7

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NC

Nguyễn Châu Mỹ Linh

10 tháng 11 2018

Tinh: a) \(\dfrac{7}{8}.\left(\dfrac{2}{12}+\dfrac{4}{10}\right)\) b) \(\dfrac{3}{2}-\dfrac{5}{6}:\left(\dfrac{1}{2}\right)^2+\sqrt{4}\) c) \(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{19}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\) d) \(\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\) e) \(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)+28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\) GIUP MK T ^...

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#Toán lớp 7

1

KK

Kẹo Kẹo Mút

21 tháng 12 2018

a)\(\dfrac{7}{8}.\left(\dfrac{2}{12}+\dfrac{4}{10}\right)=\dfrac{7}{8}.\left(\dfrac{10}{60}+\dfrac{24}{60}\right)=\dfrac{7}{8}.\dfrac{17}{30}=\dfrac{114}{240}\)

b)\(\dfrac{3}{2}-\dfrac{5}{6}\left(\dfrac{1}{2}\right)^2+\sqrt{4}=\dfrac{3}{2}-\dfrac{5}{6}.\dfrac{1}{4}+2=\dfrac{3}{2}-\dfrac{5}{24}+2=\dfrac{36}{24}-\dfrac{5}{24}+\dfrac{48}{24}=\dfrac{79}{24}\)c)\(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{19}{34}-1\dfrac{15}{17}+\dfrac{2}{3}=\left(\dfrac{15}{34}+\dfrac{19}{34}\right)+\left(\dfrac{7}{21}+\dfrac{2}{3}\right)-1\dfrac{15}{17}=1+\left(\dfrac{7}{21}+\dfrac{14}{21}\right)-\dfrac{32}{17}=1+1-\dfrac{32}{17}=2-\dfrac{32}{17}=\dfrac{34}{17}-\dfrac{32}{17}=\dfrac{2}{17}\)d)\(\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)=-8.\left(\dfrac{3}{4}-\dfrac{1}{4}\right):\left(\dfrac{9}{4}-\dfrac{7}{6}\right)=-8.\dfrac{2}{4}:\left(\dfrac{54}{24}-\dfrac{28}{24}\right)=-8.\dfrac{2}{4}:\dfrac{13}{12}=-4.\dfrac{12}{13}=\dfrac{-48}{13}\)e)\(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)+28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)=16\dfrac{2}{7}.\left(-\dfrac{5}{3}\right)+28\dfrac{2}{7}.\left(-\dfrac{5}{3}\right)=\left(16\dfrac{2}{7}+28\dfrac{2}{7}\right).\left(-\dfrac{5}{3}\right)=\left(\dfrac{120}{7}+\dfrac{196}{7}\right).\left(-\dfrac{5}{3}\right)=\dfrac{316}{7}.\left(-\dfrac{5}{3}\right)=-\dfrac{1580}{21}\)

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NC

Nguyễn Châu Mỹ Linh

10 tháng 11 2018

Tinh: a) \(\dfrac{7}{8}.\left(\dfrac{2}{12}+\dfrac{4}{10}\right)\) b) \(\dfrac{3}{2}-\dfrac{5}{6}:\left(\dfrac{1}{2}\right)^2+\sqrt{4}\) c) \(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{19}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\) d) \(\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\) e) \(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)+28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\) GIUP MK T ^...

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#Toán lớp 7

3

S

Satoshi

10 tháng 11 2018

bài này tự almf

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HM

Hoàng Minh Đức

11 tháng 11 2018

a) 119/240

b)1/6

c)2/17

d)-48/13

e)-520/7

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NC

Nguyễn Châu Mỹ Linh

11 tháng 11 2018

...

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#Toán lớp 7

4

MN

Mạnh Ngoáy

11 tháng 11 2018

e)\(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)+28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\)

=\(\left(16\dfrac{2}{7}+28\dfrac{2}{7}\right):\left(-\dfrac{3}{5}\right)\)

=\(\dfrac{312}{7}\)\(:\left(-\dfrac{3}{5}\right)\)

=\(-\dfrac{516}{7}\)

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MN

Mạnh Ngoáy

11 tháng 11 2018

a)\(\dfrac{7}{8}.\left(\dfrac{2}{12}+\dfrac{4}{10}\right)\)

=\(\dfrac{7}{8}.\left(\dfrac{1}{6}+\dfrac{2}{5}\right)\)

=\(\dfrac{7}{8}.\)\(\dfrac{17}{30}\)

=\(\dfrac{119}{240}\)

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H

huongff2k3

20 tháng 7 2021

tính
a)\(\dfrac{-10}{11}.\dfrac{8}{9}+\dfrac{7}{18}.\dfrac{10}{11}\)
b)\(\dfrac{3}{14}:\dfrac{1}{28}-\dfrac{13}{21}:\dfrac{1}{28}+\dfrac{29}{42}:\dfrac{1}{28}-8\)
c)\(-1\dfrac{5}{7}.15+\dfrac{2}{7}\left(-15\right)+\left(-105\right).\left(\dfrac{2}{3}-\dfrac{4}{5}+\dfrac{1}{7}\right)\)

#Toán lớp 6

3

NV

Nguyễn Văn Nam Hải

29 tháng 3

a)\(\dfrac{-10}{11}.\dfrac{8}{9}+\dfrac{7}{18}.\dfrac{10}{11}\)

=\(\dfrac{10}{11}.\dfrac{-8}{9}+\dfrac{7}{18}.\dfrac{10}{11}\)

=\(\dfrac{10}{11}(\dfrac{-8}{9}+\dfrac{7}{18})\)

=\(\dfrac{10}{11}.\dfrac{-1}{2}\)

=\(\dfrac{-5}{11}\)

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NT

Nguyễn Thị Thương Hoài

Giáo viên VIP

7 tháng 8

b;

B = \(\dfrac{3}{14}\) : \(\dfrac{1}{28}\) - \(\dfrac{13}{21}\): \(\dfrac{1}{28}\) + \(\dfrac{29}{42}\) : \(\dfrac{1}{28}\) - 8

B = (\(\dfrac{3}{14}\) - \(\dfrac{13}{21}\) + \(\dfrac{29}{42}\)) - 8

B = (\(\dfrac{9}{42}\) - \(\dfrac{26}{42}\) + \(\dfrac{29}{42}\)) - 8

B = (\(\dfrac{-17}{42}\) + \(\dfrac{29}{42}\)) - 8

B = \(\dfrac{2}{7}\) - 8

B = \(\dfrac{2}{7}-\dfrac{56}{7}\)

B = - \(\dfrac{54}{7}\)

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KL

Khánh Linh

14 tháng 7 2017

BT2: Tính nhanh

15) \(\left(\dfrac{1}{2}-\dfrac{13}{14}\right):\dfrac{5}{7}-\left(-\dfrac{2}{21}+\dfrac{1}{7}\right):\dfrac{5}{7}\)

16)\(\dfrac{3}{5}:\left(\dfrac{-1}{15}-\dfrac{1}{6}\right)+\dfrac{3}{5}:\left(\dfrac{-1}{3}-1\dfrac{1}{15}\right)\)

#Toán lớp 6

1

NL

Nguyễn Lê Phước Thịnh

21 tháng 5 2022

15: \(=\dfrac{7-13}{14}\cdot\dfrac{7}{5}-\dfrac{-2+3}{21}\cdot\dfrac{7}{5}\)

\(=\dfrac{7}{5}\left(-\dfrac{6}{14}-\dfrac{1}{21}\right)\)

\(=\dfrac{7}{5}\cdot\dfrac{-10}{21}=\dfrac{-2}{3}\)

16: \(=\dfrac{3}{5}:\dfrac{-2-5}{30}+\dfrac{3}{5}:\left(\dfrac{-1}{3}-\dfrac{16}{15}\right)\)

\(=\dfrac{3}{5}\cdot\dfrac{-30}{7}+\dfrac{3}{5}:\dfrac{-5-16}{15}\)

\(=\dfrac{3}{5}\cdot\dfrac{-30}{7}+\dfrac{3}{5}\cdot\dfrac{-5}{7}\)

\(=\dfrac{3}{5}\cdot\left(-5\right)=-3\)

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HH

hello hello

25 tháng 7 2018

câu 1 . Thực hiện phép tính a. 0,05 + 5 - \(\dfrac{1}{2}\) b. \(\dfrac{6}{15}-\dfrac{7}{8}+3-\dfrac{3}{5}-\dfrac{2}{16}\) c. \(\dfrac{3}{5}.\dfrac{15}{7}-\dfrac{15}{7}.\dfrac{8}{5}\) d. \(\dfrac{2}{5.7}+\dfrac{2}{7.9}+\dfrac{2}{9.11}+....+\dfrac{2}{93.99}\) e. \(\dfrac{7}{4}:\dfrac{-9}{8}-\dfrac{3}{9}\) f. \(\dfrac{15}{17}.\dfrac{19}{21}+\dfrac{19}{21}.\dfrac{2}{17}+\dfrac{13}{21}\) g....

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#Toán lớp 7

1

PK

phạm khánh linh

27 tháng 7 2018

a. = 1/20 + 5 - 1/2

= 101/20 - 1/2

= 91/20

b. = ( 6/15 - 3/5) - ( 7/8 + 2/16) + 3

= -1/5 - 1 + 3

= 9/5

c. = 15/7 . ( 3/5 - 8/5)

= 15/7 . ( -1)

= - 15/7

e. = -14/9 - 3/9

= -17/9

f. = 19/21 . ( 15/17 + 2/17) + 13/21

= 19/21 . 1 + 13/21

= 32/21

g. = 43/12 : 2 + 5/24

= 43/24 + 5/24

= 2

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D

dream

10 tháng 3 2021

Câu 1 :\(\dfrac{-5}{7}.\dfrac{7}{-45}\);\(\dfrac{-3}{10}.\left(-30\right)\);\(-12.\dfrac{-2}{36}\)Câu 2: \(\dfrac{3}{4}+\dfrac{1}{8}.\dfrac{-16}{5};\dfrac{7}{15}-\dfrac{18}{21}.\dfrac{7}{9}\)Câu 3: \(\left(\dfrac{-5}{9}+\dfrac{3}{5}\right).\dfrac{3}{10};\left(\dfrac{3}{9}-\dfrac{2}{5}\right).\dfrac{-3}{10}\)Câu 4: \(\left(\dfrac{3}{7}+\dfrac{1}{3}\right).\left(\dfrac{1}{8}-\dfrac{1}{2}\right);\left(\dfrac{-9}{12}-\dfrac{16}{30}\right).\left(\dfrac{-18}{22}-\dfrac{6}{11}\right)\)Càn...

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#Toán lớp 6

1

TM

Trần Mạnh

10 tháng 3 2021

Câu 1:

\(-\dfrac{5}{7}\cdot\dfrac{7}{-45}=\dfrac{1}{9}\) ; \(-\dfrac{3}{10}\cdot-30=9\) ; \(-12\cdot-\dfrac{2}{36}=\dfrac{2}{3}\)

Caau2;3;4;5,... tự bấm máy tính là ra

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