\(\frac{13}{21}\)+\(\frac{8}{21}\):\(\fr...">
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12 tháng 8 2017

\(\frac{13}{21}\)+   \(\frac{8}{21}\) :   \(\frac{16}{21}\)

\(\frac{13}{21}\)\(\left(\frac{8}{21}:\frac{16}{21}\right)\)=   \(\frac{13}{21}\)+   \(\frac{1}{2}\)

=   \(\frac{47}{42}\)

\(\frac{36}{35}\):   \(\frac{8}{3}\)\(\frac{36}{35}\):   \(\frac{6}{11}\)

=   \(\frac{27}{70}\)-   \(\frac{66}{35}\)=   \(-\frac{3}{2}\)

12 tháng 8 2017

Bản quyền chính cấm sao chép và copy dưới mọi hình thức

24 tháng 5 2020

a)

13/36 + 17/45 + -23/20

= 133/180 + -23/20

= -37/90

b)

18/35 + -11/21 + -23/20

= -1/105 + -23/20

= -487/420

21 tháng 1 2018

\(E=\left(\frac{-2}{3}.\frac{-9}{10}\right).\left(\frac{-5}{6}.\frac{-14}{15}\right).\left(\frac{-20}{21}.\frac{-27}{28}\right).\frac{-35}{36}\)

\(E=\frac{3}{5}.\frac{7}{9}.\frac{45}{49}.\frac{-35}{36}\)

\(E=\left(\frac{3}{5}.\frac{-35}{36}\right).\left(\frac{7}{9}.\frac{45}{49}\right)\)

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

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

vậy \(E=\frac{-5}{12}\)

21 tháng 1 2018

E=-2/3.-5/6.-9/10.-14/15.-20/21.-27/28.-35/36

=-2/3.-5/2.3.-3.3/2.5.-2.7/3.5.-4.5/3.7.3.3.3/4.7.-5.7/4.3.3

=-5/12

16 tháng 6 2017

a) \(\frac{13}{26}-\frac{1}{3}-\frac{1}{2}+\frac{7}{21}\)
\(=\frac{1}{2}-\frac{1}{3}-\frac{1}{2}+\frac{1}{3}\)
\(=\frac{1}{2}-\frac{1}{2}+\frac{1}{3}-\frac{1}{3}\)
\(=0+0\)
\(=0\)

b) \(\left(\frac{-5}{12}+\frac{6}{11}\right)+\left(\frac{7}{17}+\frac{5}{17}+\frac{5}{12}\right)\)
\(=\frac{-5}{12}+\frac{6}{11}+\frac{7}{17}+\frac{5}{17}+\frac{5}{12}\)
\(=\left(\frac{-5}{12}+\frac{5}{12}\right)+\left(\frac{7}{17}+\frac{5}{17}\right)+\frac{6}{11}\)
\(=0+\frac{12}{17}+\frac{6}{11}\)
\(=\frac{132}{187}+\frac{102}{187}\)
\(=\frac{234}{187}\)

c) \(\left(\frac{13}{5}+\frac{7}{16}\right)-\left(\frac{11}{16}-\frac{12}{10}\right)\)
\(=\left(\frac{13}{5}+\frac{7}{16}\right)-\left(\frac{11}{16}-\frac{6}{5}\right)\)
\(=\frac{13}{5}+\frac{7}{16}-\frac{11}{16}+\frac{6}{5}\)
\(=\left(\frac{13}{5}+\frac{6}{5}\right)+\left(\frac{7}{16}-\frac{11}{16}\right)\)
\(=\frac{19}{5}+\left(\frac{-4}{16}\right)\)
\(=\frac{19}{5}-\frac{1}{4}\)
\(=\frac{76}{20}-\frac{5}{20}\)
\(=\frac{71}{20}\)

d) \(-\left(\frac{3}{10}-\frac{6}{11}\right)-\left(\frac{21}{30}-\frac{5}{11}\right)\)
\(=-\left(\frac{3}{10}-\frac{6}{11}\right)-\left(\frac{7}{10}-\frac{5}{11}\right)\)
\(=-\frac{3}{10}+\frac{6}{11}-\frac{7}{10}+\frac{5}{11}\)
\(= \left(-\frac{3}{10}-\frac{7}{10}\right)+\left(\frac{6}{11}+\frac{5}{11}\right)\)
\(=\frac{-10}{10}+\frac{11}{11}\)
\(=-1+1\)
\(=0\)

3 tháng 1 2017

a) \(\left(\frac{1}{4}+-\frac{5}{13}\right)+\left(\frac{2}{11}+-\frac{8}{13}+\frac{3}{4}\right)\)

\(=\frac{2}{11}+\left(\frac{1}{4}+\frac{3}{4}\right)+\left(-\frac{5}{13}+-\frac{8}{13}\right)\)

\(=\frac{2}{11}+1+\left(-1\right)\)

\(=\frac{2}{11}+0\)

\(=\frac{2}{11}\)

b) \(\left(\frac{21}{31}+-\frac{16}{7}\right)+\left(\frac{44}{53}+\frac{10}{31}\right)+\frac{9}{53}\)

\(=-\frac{16}{7}+\left(\frac{21}{31}+\frac{10}{31}\right)+\left(\frac{44}{53}+\frac{9}{53}\right)\)

\(=-\frac{16}{7}+1+1\)

\(=-\frac{16}{7}+2\)

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

c) \(\frac{\frac{9}{45}-\frac{4}{13}-\frac{1}{3}}{\frac{3}{13}-\frac{1}{15}+\frac{2}{3}}\)

\(=-\frac{43}{81}\)

3 tháng 1 2017

:v sướng