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26 tháng 11 2018

Ta có : \(\frac{2}{3}x-70\frac{10}{11}(\frac{131313}{151515}+\frac{131313}{353535}+\frac{131313}{999999})=-5\)

          \(\frac{2}{3}x-70\frac{10}{11}\cdot(\frac{13}{15}+\frac{13}{35}+\frac{13}{99})=-5\)

          \(\frac{2}{3}x-70\frac{10}{11}\cdot(\frac{13}{3\cdot5}+\frac{13}{5\cdot7}+\frac{13}{9\cdot11})=-5\)

           \(\frac{2}{3}x-70\frac{10}{11}\cdot\left[\frac{13}{2}\cdot(\frac{2}{3\cdot5}+\frac{2}{5\cdot7}+\frac{2}{9\cdot11})\right]=-5\)

           \(\frac{2}{3}x-70\frac{10}{11}\cdot\left[\frac{13}{2}\cdot(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11})\right]=-5\)

           \(\frac{2}{3}x-70\frac{10}{11}\cdot[\frac{13}{2}\cdot(\frac{1}{3}-\frac{1}{11})]=-5\)

            \(\frac{2}{3}x-70\frac{10}{11}\cdot\left[\frac{13}{2}\cdot\frac{8}{33}\right]=-5\)

            \(\frac{2}{3}x-\frac{780}{11}\cdot\frac{52}{33}=-5\)

               \(\frac{2}{3}x-\frac{13520}{121}=-5\)

Rồi còn khúc đó bạn tự làm

            

26 tháng 11 2018

#R#b em bó tay

                                      \(\frac{3}{5}x-\frac{13}{9}:\left(\frac{131313}{151515}+\frac{131313}{353535}+\frac{131313}{636363}\right)=-10\)

                                 <=> \(\frac{3}{5}x-\frac{13}{9}:\left(\frac{13}{15}+\frac{13}{35}+\frac{13}{63}\right)=-10\)

                                 <=> \(\frac{3}{5}x-\frac{13}{9}:13:\left(\frac{1}{15}+\frac{1}{35}+\frac{1}{63}\right)=-10\)

                                 <=> \(\frac{3}{5}x-\frac{1}{9}:\left(\frac{21}{315}+\frac{9}{315}+\frac{5}{315}\right)=-10\)

                                 <=> \(\frac{3}{5}x-\frac{1}{9}:\frac{35}{315}=-10\)

                                 <=> \(\frac{3}{5}x-\frac{1}{9}:\frac{1}{9}=-10\)

                                 <=> \(\frac{3}{5}x-1=-10\)

                                 <=> \(\frac{3}{5}x=-9\)

                                 <=> \(x=-15\)

Vậy x = -15.

20 tháng 6 2018

\(\frac{3}{5}x-1\frac{4}{9}:\left(\frac{131313}{151515}+\frac{131313}{353535}+\frac{131313}{636363}\right)=-10\)

\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left(\frac{13}{15}+\frac{13}{35}+\frac{13}{63}=-10\right)\)

\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left[\frac{13}{2}\left(\frac{2}{15}+\frac{2}{35}+\frac{2}{63}\right)\right]=-10\)

\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left[\frac{13}{2}\left(\frac{2}{3.5}+\frac{2}{.57}+\frac{2}{7.9}\right)\right]=-10\)

\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left[\frac{13}{2}\left(\frac{1}{3}-\frac{1}{9}\right)\right]=-10\)

\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left(\frac{13}{2}.\frac{2}{9}\right)=-10\)

\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\frac{26}{18}=-10\)

\(\Leftrightarrow\frac{3}{5}x-1=-10\)

\(\Leftrightarrow\frac{3}{5}x=-10+1\)

\(\Leftrightarrow\frac{3}{5}x=-9\)

\(\Rightarrow x=-9:\frac{3}{5}\)

\(\Rightarrow x=-15\)

Vậy \(x=-15\)

27 tháng 3 2018

\(\dfrac{2}{3}x-70\dfrac{10}{11}:\left(\dfrac{131313}{151515}+\dfrac{131313}{353535}+\dfrac{131313}{636363}+\dfrac{131313}{999999}\right)=-5\\ \Rightarrow\dfrac{2}{3}x-\dfrac{780}{11}:\left(\dfrac{13}{15}+\dfrac{13}{35}+\dfrac{13}{63}+\dfrac{13}{99}\right)=-5\\ \Rightarrow\dfrac{2}{3}x-\dfrac{780}{11}:13\left(\dfrac{1}{15}+\dfrac{1}{35}+\dfrac{1}{63}+\dfrac{1}{99}\right)=-5\\ \Rightarrow\dfrac{2}{3}x-\dfrac{780}{11}:13.\dfrac{4}{33}=-5\\ \Rightarrow\dfrac{2}{3}x-\dfrac{780}{11}:\dfrac{52}{33}=-5\\ \Rightarrow\dfrac{2}{3}x-45=-5\\ \Rightarrow\dfrac{2}{3}x=40\\ \Rightarrow x=60\)

27 tháng 9 2016

\(\frac{\frac{4}{17}}{\frac{5}{17}}-\frac{\frac{4}{177}}{\frac{5}{177}}-\frac{\frac{4}{1779}}{\frac{5}{1779}}+\frac{131313}{151515}\)

\(=\)\(\frac{4}{1445}-\frac{4}{156645}-\frac{4}{15824205}\)\(+\frac{131313}{151515}\)

\(=\)\(0,8694090445\)

1 tháng 9 2015

Minh Triều giải từng câu đi 

4 tháng 1 2017


A=(-1).(-1)3.....(-1)2013.(-1)2.....(-1)2012 
A=(-1).1
A=-1

b: Ta có: \(B=\dfrac{1}{4\cdot9}+\dfrac{1}{9\cdot14}+...+\dfrac{1}{64\cdot69}\)

\(=\dfrac{1}{5}\left(\dfrac{5}{4\cdot9}+\dfrac{5}{9\cdot14}+...+\dfrac{5}{64\cdot69}\right)\)

\(=\dfrac{1}{5}\left(\dfrac{1}{4}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{14}+...+\dfrac{1}{64}-\dfrac{1}{69}\right)\)

\(=\dfrac{1}{5}\cdot\dfrac{65}{4\cdot69}\)

\(=\dfrac{13}{276}\)

26 tháng 9 2021

\(A=\dfrac{2}{1\cdot4}+\dfrac{2}{4\cdot7}+...+\dfrac{2}{97\cdot100}\\ A=\dfrac{2}{3}\left(\dfrac{3}{1\cdot4}+\dfrac{3}{4\cdot7}+...+\dfrac{3}{97\cdot100}\right)\\ A=\dfrac{2}{3}\left(1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{7}+...+\dfrac{1}{97}-\dfrac{1}{100}\right)\\ A=\dfrac{2}{3}\left(1-\dfrac{1}{100}\right)=\dfrac{2}{3}\cdot\dfrac{99}{100}=\dfrac{33}{50}\\ B=\dfrac{1}{4\cdot9}+\dfrac{1}{9\cdot14}+...+\dfrac{1}{64\cdot69}\\ B=\dfrac{1}{5}\left(\dfrac{5}{4\cdot9}+\dfrac{5}{9\cdot14}+...+\dfrac{5}{64\cdot69}\right)\\ B=\dfrac{1}{5}\left(\dfrac{1}{4}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{14}+...+\dfrac{1}{64}-\dfrac{1}{69}\right)\\ B=\dfrac{1}{5}\left(\dfrac{1}{4}-\dfrac{1}{69}\right)=\dfrac{1}{5}\cdot\dfrac{65}{276}=\dfrac{13}{276}\)

\(C=70\left(\dfrac{13}{56}+\dfrac{13}{72}+\dfrac{13}{90}\right)=70\cdot13\left(\dfrac{1}{56}+\dfrac{1}{72}+\dfrac{1}{90}\right)\\ C=910\left(\dfrac{1}{7\cdot8}+\dfrac{1}{8\cdot9}+\dfrac{1}{9\cdot10}\right)\\ C=910\left(\dfrac{1}{7}-\dfrac{1}{8}+\dfrac{1}{8}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{10}\right)\\ C=910\left(\dfrac{1}{7}-\dfrac{1}{10}\right)=910\cdot\dfrac{3}{70}=39\)

21 tháng 4 2018

\(A=1.2.3...9-1.2.3..8-1.2.3....8.8\)

\(A=1.2.3...8.\left(9-1-8\right)\)

\(A=0.1.2.3.....8=0\)

21 tháng 4 2018

\(B=\left(3.4.2^{16}\right)^2=\left(3.2^2.2^{16}\right)^2=\left(3.2^{18}\right)^2=9.2^{36}\)

18 tháng 9 2020

giup toi

18 tháng 9 2020

\(\frac{3}{4}x-14\frac{2}{3}:\left(\frac{11}{15}+\frac{1111}{3535}+\frac{111111}{636363}\right)=12\)

\(\frac{3}{4}x-\frac{44}{3}:\left(\frac{11}{15}+\frac{11}{35}+\frac{11}{63}\right)=12\)

\(\frac{3}{4}x-\frac{44}{3}:\frac{11}{9}=12\)

\(\frac{3}{4}x-12=12\)

\(\frac{3}{4}x=12+12\)

\(\frac{3}{4}x=24\)

\(x=24:\frac{3}{4}\)

\(x=32\)

vậy \(x=32\)