K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

31 tháng 5 2016

c.

\(\frac{1}{3}\times\frac{5}{7}-\frac{7}{27}\times\frac{36}{14}\)

\(=\frac{1}{3}\times\frac{5}{7}-\frac{7}{3\times9}\times\frac{4\times9}{7\times2}\)

\(=\frac{1}{3}\times\frac{5}{7}-\frac{1}{3}\times\frac{4}{6}\)

\(=\frac{1}{3}\times\left(\frac{5}{7}-\frac{4}{6}\right)\)

\(=\frac{1}{3}\times\left(\frac{30-38}{42}\right)\)

\(=\frac{1}{3}\times\frac{-8}{42}\)

\(=-\frac{4}{63}\)

Chúc bạn học tốtok

31 tháng 5 2016

Sorry nha, tại mik làm biếng quábucminh

9 tháng 8 2017

A) \(\frac{1}{2}\cdot\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{27}\right)\) 

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

\(=\frac{1}{4}\)

B)   \(\left(\frac{-5}{28}+1.75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right)\)

\(=\left(\frac{-5}{28}+\frac{7}{4}+\frac{8}{35}\right):\frac{-69}{20}\)

\(=\frac{14}{5}:\frac{-69}{20}\)

\(=\frac{-56}{69}\)

29 tháng 4 2018

\(a,\)\(\frac{1}{2}.\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{37}\right)\)

\(\Rightarrow\frac{1}{2}.\left(\frac{2.259}{2331}+\frac{3.333}{2331}-\frac{5.63}{2331}\right)\)

\(\Rightarrow\frac{1}{2}.\left(\frac{518}{2331}+\frac{999}{2331}-\frac{315}{2331}\right)\)

\(\Rightarrow\frac{1}{2}.\left(\frac{518+999-315}{2331}\right)\)

\(\Rightarrow\frac{1}{2}.\frac{1202}{2331}\)

\(\Rightarrow\frac{601}{2331}\)

29 tháng 4 2018

\(b,\)\(\left(-\frac{5}{28}+1,75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right)\)

\(\Rightarrow\frac{9}{5}:\left(-\frac{69}{20}\right)\)

\(=-\frac{12}{23}\)

\(c,\)\(\frac{1}{3}.\frac{1}{5}-\frac{7}{27}.\frac{36}{14}\)

   \(=\frac{1}{15}-\frac{2}{3}\)

\(=\frac{1}{15}-\frac{10}{15}=-\frac{9}{15}=-\frac{3}{5}\)

\(d,\)\(70,5-528:\frac{15}{2}\)

\(=70,5-\frac{352}{5}\)

\(=\frac{1}{10}\)

16 tháng 4 2017

mình chỉ làm được câu đầu tiên thôi

rồi cậu làm tiếp nhé!!!!!!!!!!!!

=\(\frac{1}{2}.\left(\frac{42}{189}+\frac{81}{189}-\frac{35}{189}\right)\)

a: \(=\left(-\dfrac{25}{140}+\dfrac{245}{140}+\dfrac{32}{140}\right)\cdot\dfrac{-69}{20}\)

\(=\dfrac{252}{140}\cdot\dfrac{-69}{20}\)

\(=\dfrac{9}{5}\cdot\dfrac{-69}{20}=\dfrac{-621}{100}\)

b: \(=\left(6-2-\dfrac{4}{5}\right)\cdot\dfrac{25}{8}-\dfrac{8}{5}\cdot4\)

\(=\dfrac{16}{5}\cdot\dfrac{25}{8}-\dfrac{32}{5}=\dfrac{18}{5}\)

c: \(=\left(\dfrac{2}{24}+\dfrac{18}{24}+\dfrac{14}{24}\right):\dfrac{-17}{8}\)

\(=\dfrac{34}{24}\cdot\dfrac{-8}{17}=\dfrac{-1}{3}\cdot2=-\dfrac{2}{3}\)

a) Ta có: \(\frac{-1}{12}-\left(2\frac{5}{8}-\frac{1}{3}\right)\)

\(=-\frac{1}{12}-\frac{21}{8}+\frac{1}{3}\)

\(=\frac{-6}{72}-\frac{189}{72}+\frac{24}{72}\)

\(=-\frac{19}{8}\)

b) Ta có: \(-1,75-\left(\frac{-1}{9}-2\frac{1}{18}\right)\)

\(=\frac{-7}{4}+\frac{1}{9}+\frac{37}{18}\)

\(=\frac{-63}{36}+\frac{4}{36}+\frac{74}{36}\)

\(=\frac{5}{12}\)

c) Ta có: \(\frac{2}{5}+\frac{-4}{3}+\frac{-1}{2}\)

\(=\frac{12}{30}+\frac{-40}{30}+\frac{-15}{30}\)

\(=-\frac{43}{30}\)

d) Ta có: \(\frac{3}{12}-\left(\frac{6}{15}-\frac{3}{10}\right)\)

\(=\frac{3}{12}-\frac{6}{15}+\frac{3}{10}\)

\(=\frac{15}{60}-\frac{24}{60}+\frac{18}{60}\)

\(=\frac{3}{20}\)

e) Ta có: \(\left(8\frac{5}{11}+3\frac{5}{8}\right)-3\frac{5}{11}\)

\(=\frac{93}{11}+\frac{29}{8}-\frac{38}{11}\)

\(=5+\frac{29}{8}=\frac{40}{8}+\frac{29}{8}=\frac{69}{8}\)

f) Ta có: \(\frac{4}{9}:\left(-\frac{1}{7}\right)+6\frac{5}{9}:\left(-\frac{1}{7}\right)\)

\(=\frac{4}{9}\cdot\left(-7\right)+\frac{59}{9}\cdot\left(-7\right)\)

\(=\left(-7\right)\cdot\left(\frac{4}{9}+\frac{59}{9}\right)=\left(-7\right)\cdot7=-49\)

g) Ta có: \(\frac{-1}{4}\cdot13\frac{9}{11}-0,25\cdot6\frac{2}{11}\)

\(=\frac{-1}{4}\cdot\frac{152}{11}+\frac{-1}{4}\cdot\frac{68}{11}\)

\(=\frac{-1}{4}\cdot\left(\frac{152}{11}+\frac{68}{11}\right)=-\frac{1}{4}\cdot20=-5\)

h) Ta có: \(5\frac{27}{5}+\frac{27}{23}+0,5-\frac{5}{27}+\frac{16}{23}\)

\(=\frac{52}{5}+\frac{27}{23}+\frac{1}{2}-\frac{5}{27}+\frac{16}{23}\)

\(=\frac{52}{5}+\frac{43}{23}+\frac{1}{2}-\frac{5}{27}\)

\(=\frac{64584}{6210}+\frac{11610}{6210}+\frac{3105}{6210}-\frac{1150}{6210}\)

\(=\frac{78149}{6210}\)

i) Ta có: \(\frac{3}{8}\cdot27\frac{1}{5}-51\frac{1}{5}\cdot\frac{3}{8}+19\)

\(=\frac{3}{8}\cdot\frac{136}{5}-\frac{3}{8}\cdot\frac{206}{5}+\frac{3}{8}\cdot\frac{152}{3}\)

\(=\frac{3}{8}\cdot\left(\frac{136}{5}-\frac{206}{5}+\frac{152}{3}\right)=\frac{3}{8}\cdot\frac{110}{3}\)

\(=\frac{55}{4}\)