a, \(\frac{-3}{7}+\frac{5}{13}-\frac{4}{7}+\frac{8}{13}\)

\(=\frac{-3}{7}-\frac{4}{7}+\frac{5}{13}+\frac{8}{13}\)

\(=-\frac{7}{7}+\frac{13}{13}=-1+1=0\)

b, \(\frac{-5}{14}-\frac{2}{-14}+\frac{1}{8}+\frac{1}{8}\)

\(=\frac{-5}{14}+\frac{2}{14}+\frac{1}{8}+\frac{1}{8}\)

\(=-\frac{3}{14}+\frac{1}{4}=\frac{1}{28}\)

c,\(-\frac{5}{13}-\left(\frac{3}{5}+\frac{3}{13}-\frac{4}{10}\right)\)

\(=-\frac{5}{13}-\frac{3}{13}-\frac{3}{5}+\frac{4}{10}\)

\(=-\frac{8}{13}-\frac{3}{5}+\frac{4}{10}=-\frac{79}{65}+\frac{4}{10}=-\frac{53}{65}\)

d, \(\left[\left(\frac{1}{8}-\frac{9}{7}+\frac{4}{6}-\frac{12}{7}-\frac{1}{2}\right)+\frac{5}{9}\right]\)

\(=\left[\left(\frac{1}{8}-\frac{9}{7}+\frac{2}{3}-\frac{12}{7}-\frac{1}{2}\right)+\frac{5}{9}\right]\)

\(=\left[\left(\frac{1}{8}-\frac{1}{2}-\frac{9}{7}-\frac{12}{7}+\frac{2}{3}\right)+\frac{5}{9}\right]\)

\(=-\frac{65}{24}+\frac{5}{9}=-2\frac{11}{72}\)

a)-3/7+5/13-4/7+8/13

=-3/7-4/7+5/13+8/13

=-7/7+13/13

=-1+1

=0

khó quá mk giải miết mà không ra

khó vãi

\(\frac{6}{5}-\frac{1}{4}+\frac{4}{5}-\frac{3}{4}\)

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

\(=2-1\)

\(=1\)

\(\frac{7}{9}-\frac{5}{12}+\frac{2}{9}-\frac{7}{12}\)

\(=\left(\frac{7}{9}+\frac{2}{9}\right)-\left(\frac{5}{12}+\frac{7}{12}\right)\)

\(=1-1\)

\(=0\)

các câu sau tương tự

A=1

B=0

C=ÂM 8/15

D=0

E=2

F=3/2

H=2/3 

LẦN SAU CHO KHÓ SÍU NHA LỚP 5 CŨNG LÀM ĐC

Ta có:

5⁷+5⁸+5⁹

=5⁷(1+5+5²)

=5⁷.31

Vì 31 chia hết cho 31=)5⁷.31 chia hết cho 31

Vậy 5⁷+5⁸+5⁹ chia hết cho 31

Học tốt nhé

c)\(^{5^7+5^8+5^9}\)

= \(5^7\left(1+5+5^2\right)\)

= \(5^7.31\)

\(5^7.31⋮31\)

\(\Rightarrow\)\(5^7+5^8+5^9\)\(⋮\)\(31\)

(-5/11:13/8-5/11:13/5)+-1/33

= (-5/11.8/13-5/11.5/13)+-1/33

= -5/11.(8/13+5/13)+-1/33

=-5/11.1+-1/33

=-5/11+-1/33

=-16/33

mk lm đại ko bt đúng hay ko

test lại dùm mk nha

con điên ngu như chó

\(=>A=\left(\frac{1}{6}-\frac{1}{6}\right)-\left(\frac{3}{8}-\frac{3}{8}\right)+\left(\frac{7}{10}-\frac{7}{10}\right)-\left(\frac{9}{11}-\frac{9}{11}\right)+\left(\frac{5}{13}-\frac{5}{13}\right)-\frac{11}{19}\)

\(=>A=-\frac{11}{19}\)

Học tốt nha 

Trả lời:

\(\left(\frac{-5}{11}\text{÷}\frac{13}{8}-\frac{5}{11}\text{÷}\frac{13}{5}\right)+\frac{-1}{33}\)

\(=\left(\frac{-5}{11}.\frac{8}{13}+\frac{-5}{11}.\frac{5}{13}\right)+\frac{-1}{33}\)

\(=\frac{-5}{11}.\left(\frac{8}{13}+\frac{5}{13}\right)+\frac{-1}{33}\)

\(=\frac{-5}{11}+\frac{-1}{33}\)

\(=\frac{-15-1}{33}\)

\(=\frac{-16}{33}\)

#Huyền Anh