\(\frac13+\frac37+\frac{1}{7*2}+\frac{5}{2*13}+\frac{3}{13*4}+\frac{5}{4*21}\)
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Khách

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14 tháng 4

Ờ ừm, hình như bé ra đề bị lỗi á

20 tháng 4

Ta có: \(\frac13+\frac37+\frac{1}{7\cdot2}+\frac{5}{2\cdot13}+\frac{3}{13\cdot4}+\frac{5}{4\cdot21}\)

\(=4\left(\frac{1}{3\cdot4}+\frac{3}{4\cdot7}+\frac{1}{7\cdot8}+\frac{5}{8\cdot13}+\frac{3}{13\cdot16}+\frac{5}{16\cdot21}\right)\)

\(=4\left(\frac13-\frac14+\frac14-\frac17+\frac17-\frac18+\frac18-\frac{1}{13}+\frac{1}{13}-\frac{1}{16}+\frac{1}{16}-\frac{1}{21}\right)\)

\(=4\left(\frac13-\frac{1}{21}\right)=4\cdot\frac{7-1}{21}=4\cdot\frac{6}{21}=\frac{24}{21}=\frac87\)

17 tháng 12 2019

Thực hiện phép tính ( bằng cách hợp lí nếu có thể):

a, \(5\frac{4}{13}.15\frac{3}{41}-5\frac{4}{13}.2\frac{3}{41}\)

\(=5\frac{4}{13}\left(15\frac{3}{41}-2\frac{3}{41}\right)\)

\(=15\frac{4}{13}\left(\frac{618}{41}-\frac{85}{41}\right)\)

\(=\frac{69}{13}.13\)

\(=69\)

b, \(6.\left(-\frac{1}{3}\right)^2-\left(\frac{1}{4}:2-\frac{7}{16}.\frac{-4}{21}\right)\)

\(=6.\frac{1}{9}-\left(\frac{1}{8}-\frac{-1}{12}\right)\)

\(=\frac{2}{3}-\left(\frac{3}{24}-\frac{-2}{24}\right)\)

\(=\frac{2}{3}-\frac{5}{24}\)

\(=\frac{16}{24}-\frac{5}{24}\)

\(=\frac{11}{24}\)

Chúc bạn hok tốt!!! lưu khánh huyền

17 tháng 12 2019

kcj

17 tháng 12 2016

a) \(\frac{17}{9}-\frac{17}{9}:\left(\frac{7}{3}+\frac{1}{2}\right)\)

= \(\frac{17}{9}-\frac{17}{9}:\frac{17}{6}\)

= \(\frac{17}{9}-\frac{2}{3}\)

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

b) \(\frac{4}{3}.\frac{2}{5}-\frac{3}{4}.\frac{2}{5}\)

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

= \(\frac{2}{5}.\frac{7}{12}\)

= \(\frac{7}{30}\)

Mình lười làm quá, hay mình nói kết quả cho bn thôi nha

c) -6

d) 3

e) 3

g) 12

h) \(\frac{23}{18}\)

i) \(\frac{-69}{20}\)

k) \(\frac{-1}{2}\)

l) \(\frac{49}{5}\)

6 tháng 7 2025

Bài 1:

A = \(\frac15\) + \(\frac{3}{17}\) - \(\frac43\) + (\(\frac45\) - \(\frac{3}{17}\) + \(\frac13\)) - \(\frac17\) + (- \(\frac{14}{30}\))

A = \(\frac15\) + \(\frac{3}{17}\) - \(\frac43\) + \(\frac45\) - \(\frac{3}{17}\) + \(\frac13\) - \(\frac17\) - \(\frac{14}{30}\)

A = (\(\frac15\) + \(\frac45\)) + (\(\frac{3}{17}\) - \(\frac{3}{17}\)) - (\(\frac43-\frac13\)) - \(\frac{30}{210}\) - \(\frac{98}{210}\)

A = 1 + 0 - 1 - (\(\frac{30}{210}+\frac{98}{210}\))

A = 1 - 1 - \(\frac{228}{210}\)

A = 0 - \(\frac{128}{210}\)

A = - \(\frac{64}{105}\)

6 tháng 7 2025

Bài 2:

B= (\(\frac58\) - \(\frac{4}{12}\) + \(\frac32\)) - (\(\frac58\) + \(\frac{9}{13}\)) - (\(\frac{-3}{2}\)) + \(\frac{7}{-15}\)

B = \(\frac58\) - \(\frac{4}{12}\) + \(\frac32\) - \(\frac58\) - \(\frac{9}{13}\) + \(\frac32\) - \(\frac{7}{15}\)

B = (\(\frac58\) - \(\frac58\)) + (\(\frac32\) + \(\frac32\)) - (\(\frac13\) + \(\frac{9}{13}\) + \(\frac{7}{15}\))

B = 0 + 3 - (\(\frac{65}{195}\) + \(\frac{135}{195}\) + \(\frac{91}{195}\))

B = 3 - (\(\frac{200}{195}\) + \(\frac{91}{195}\))

B = 3 - \(\frac{97}{65}\)

B = \(\frac{195}{65}\) - \(\frac{97}{65}\)

B = \(\frac{98}{65}\)

5 tháng 9 2019

A = 5/7.(1+9/13) − 5/7.9/13

A= 5/7.(1+9/13 - 9/13)

A = 5/7.1

A = 5/7

B = 11/24 − 5/41 + 13/24 + 0.5 − 36/41

B = (11/24 + 13/24) - (5/41 + 36/41) + 0.5

B = 1 - 1 + 0.5

B = 0.5

C = −4/13.5/17 + (−12/13).4/17 + 4/13

C = 4/13.(-5/17) + (−12/13).4/17 + 4/13

C = 4/13.(-5/17 + 1) + (−12/13).4/17

C = 4/13.(−12/17) + (−12/13).4/17

C = (4.-12)/(13.17) + (−12/13).4/17

C = 4/17.(−12/13) + (−12/13).4/17

C = 4/17.(−12/13).2

C = 96/221

D = (4/3 − 3/2)2 − 2.∣−1/9∣ + (−5/18)

D = (4/3 − 3/2)2 − 2.1/9+ (−5/18)

D = -1/62 - 2/9+ (−5/18)

D = -1/12 - ( 2/9+ (−5/18) )

D = -1/12 - ( 4/18+ (−5/18) )

D = -1/12 - (-1/18)

D = -1/12 + 1/18

D = -3/36 + 2/36

D = -1/36

E = (−3/4 + 2/3):5/11 + (−1/4 + 1/3):5/11

E = (−3/4 + 2/3 + (−1/4) + 1/3):5/11

E = ((−3/4 + (−1/4)) + (2/3 + + 1/3)):5/11

E = ( - 1 + 1):5/11

E = 0:5/11

E = 0

4 tháng 9 2020

              Bài làm :

a)\(=-\frac{3}{5}+\frac{28}{5}\times\frac{9}{14}=-\frac{3}{5}+\frac{18}{5}=3\)

b)\(=\frac{55}{126}+\frac{5}{42}+\frac{4}{9}=1\)

c)\(=-\frac{51}{13}-\frac{27}{13}=-6\)

d)\(=\frac{7}{3}-11\frac{1}{4}\times\frac{2}{15}=\frac{7}{3}-\frac{3}{2}=\frac{5}{6}\)

e)\(=1\times\frac{8}{3}\times0,25=\frac{2}{3}\)

30 tháng 10 2018

=30/12+(-4/12)+3/12

=29/12