âm 2( số -2) và 4/25

\(\frac{-3}{31}+\frac{-6}{17}+\frac{1}{25}+\frac{-28}{31}+\frac{-11}{17}+\frac{-1}{5}\)

\(=\left(\frac{-3}{31}+\frac{-28}{31}\right)+\left(\frac{-6}{17}+\frac{-11}{17}\right)+\left(\frac{1}{25}+\frac{-1}{5}\right)\)

\(=\frac{-31}{31}+\frac{-17}{17}+\frac{-4}{25}\)

\(=\left(-1\right)+\left(-1\right)+\frac{-4}{25}\)

\(=\frac{\left(-25\right)+\left(-25\right)+\left(-4\right)}{25}\)

\(=\frac{-54}{25}\)

=\(-\dfrac{54}{25}\)

= -24/25

b: D=(-3/31-28/31)+(-6/17-11/17)+(1/25-5/25)

=-2-4/25=-54/25

Mik cần nhanh, mai mik hok r T^T

1) Tính nhanh 

\(A=\frac{4}{7}+\frac{3}{4}+\frac{2}{7}+\frac{5}{4}+\frac{1}{7}\)

\(=\left(\frac{4}{7}+\frac{2}{7}+\frac{1}{7}\right)+\left(\frac{3}{4}+\frac{5}{4}\right)\)

\(=1+2=3\)

Ghép tương tự vs B 

1,35326087

-2/3

0

-6/29/44

-9

nha bạn

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

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

\(= \frac{4}{4} + \frac{-13}{13} + \frac{2}{11}\)

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

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

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

\(=\frac{31}{31}+\frac{53}{53}+\frac{-16}{7}=1+1-\frac{16}{7}\)

\(=2-\frac{16}{7}=\frac{14}{7}-\frac{16}{7}=-\frac27\)

\(c,\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\frac{-2}{7}+\frac{1}{4}\)

\(= (\frac{-5}{7} + \frac{-2}{7}) + (\frac{3}{4} + \frac{1}{4}) + \frac{-1}{5}\)

\(= \frac{-7}{7} + \frac{4}{4} + \frac{-1}{5}\)

\(=-1+1-\frac{1}{5}=0-\frac15=-\frac15\)

\(\frac{-3}{31} + \frac{-6}{17} + \frac{1}{25} + \frac{-28}{31} + \frac{-11}{17} + \frac{-1}{5}\)

\(= (\frac{-3}{31} + \frac{-28}{31}) + (\frac{-6}{17} + \frac{-11}{17}) + \frac{1}{25} + \frac{-1}{5}\)

\(= \frac{-31}{31} + \frac{-17}{17} + \frac{1}{25} - \frac{5}{25}\)

\(= -1 + (-1) + \frac{-4}{25}\)

\(=-2-\frac{4}{25}=-\frac{50}{25}-\frac{4}{25}=-\frac{54}{25}\)