= \(\frac{4}{13}.\left(\frac{5}{11}+\frac{6}{11}-1\right)=\frac{4}{13}.\left(\frac{11}{11}-1\right)=\frac{4}{13}.0=0\)

Tính nhanh :

a) 

\(\left(2+\frac{-7}{13}\right)+\frac{-6}{13}\)

= \(2+\left(\frac{-7}{13}+\frac{-6}{13}\right)\)

= \(2+\frac{-13}{13}=2+\left(-1\right)\)

= 1

tk mk nha

chắc chắn đúng luôn ấy

mk đang âm rất nhiều này ! huhuhu giúp nha  

a)=1

b)=\(-\frac{1}{3}\)

c)=\(\frac{9}{29}\)

ta có \(\frac{\frac{4}{5}-\frac{4}{11}+\frac{4}{13}}{\frac{9}{5}-\frac{9}{11}+\frac{9}{13}}+\frac{\frac{5}{7}+\frac{5}{11}-\frac{5}{13}}{\frac{9}{7}+\frac{9}{11}-\frac{9}{13}}\)

       \(=\frac{4\left(\frac{1}{5}-\frac{1}{11}+\frac{1}{13}\right)}{9\left(\frac{1}{5}-\frac{1}{11}+\frac{1}{13}\right)}+\frac{5\left(\frac{1}{7}+\frac{1}{11}-\frac{1}{13}\right)}{9\left(\frac{1}{7}+\frac{1}{11}-\frac{1}{13}\right)}\)

           \(=\frac{4}{9}+\frac{5}{9}=\frac{9}{9}=1\)

A = 6/19 . -7/11 + 6/19 . -4/11 + -13/19

A = 6/19 . [-7/11 + (-4/11)] + (-13/19)

A = 6/19 . -11/11 + (-13/19)

A = 6/19 . (-1) + (-13/19)

A = -6/19 + (-13/19)

A = -19/19

A = -1

Vậy A = -1

Theo dõi mik nha!

34 −35 +37 +311 134 −135 +137 +1311

 \(=\frac{3.\left(\frac{1}{4}-\frac{1}{5}+\frac{1}{7}+\frac{1}{11}\right)}{13.\left(\frac{1}{4}-\frac{1}{5}+\frac{1}{7}+\frac{1}{11}\right)}\)

\(=\frac{3}{13}\)

\(A=\dfrac{6}{19}.\dfrac{-7}{11}+\dfrac{6}{19}.\dfrac{-4}{11}+\dfrac{-13}{19}\)

\(A=\dfrac{6}{19}.\left(\dfrac{-7}{11}+\dfrac{-4}{11}\right)+\dfrac{-13}{19}\)

\(A=\dfrac{6}{19}.-1+\dfrac{-13}{19}=\dfrac{-6}{19}+\dfrac{-13}{19}=\dfrac{-19}{19}=-1\)

B=57.−413+57.73−513.37

B=57.−413+57.73− \(\dfrac{5}{7}.\dfrac{3}{13}\)3

7

\(B=\dfrac{5}{7}.\left(\dfrac{-4}{13}+\dfrac{7}{3}-\dfrac{3}{13}\right)\)

\(B=\dfrac{5}{7}.\dfrac{70}{39}=\dfrac{350}{273}\)

Câu B ko rõ lắm

\(B=\dfrac{5}{7}.\dfrac{-4}{13}+\dfrac{5}{7}.\dfrac{7}{3}-\dfrac{5}{13}.\dfrac{3}{7}\)

\(B=\dfrac{5}{7}.\dfrac{-4}{13}+\dfrac{5}{7}.\dfrac{7}{3}-\dfrac{5}{7}.\dfrac{3}{13}\)

Rồi tiếp 2 câu rõ

a)\(\frac{-10}{13}+\frac{8}{17}-\frac{3}{13}+\frac{12}{17}-\frac{11}{20}\)                

= \(\frac{-10}{13}+\frac{8}{17}+\frac{-3}{13}+\frac{12}{17}+\frac{-11}{20}\)     

=\(\left(\frac{-10}{13}+\frac{-3}{13}\right)+\left(\frac{8}{17}+\frac{12}{17}\right)+\frac{-11}{20}\)

=\(\frac{-13}{13}+\frac{20}{17}+\frac{-11}{20}\)

= \(\frac{-127}{340}\)

b) \(\frac{3}{4}+\frac{-5}{6}-\frac{11}{-12}\)

= \(\frac{3}{4}+\frac{-5}{6}+\frac{11}{12}\)

= \(\frac{9}{12}+\frac{-10}{12}+\frac{11}{12}\)

=\(\frac{10}{12}=\frac{5}{6}\)

c) \(\left[13.\frac{4}{9}+2.\frac{1}{9}\right]-3.\frac{4}{9}\)

= \(13+2.\left(\frac{4}{9}+\frac{1}{9}\right)-3.\frac{4}{9}\)

=\(15.\frac{5}{9}-3.\frac{4}{9}\)

=\(\left[15-3.\left(\frac{5}{9}-\frac{4}{9}\right)\right]\)

=\(12.\frac{1}{9}\)

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

Chúc bạn học tốt nhea. k mik nha ! ♥☺☺

ta có

\(2.\left(\dfrac{1}{3}+\dfrac{1}{13}+\dfrac{1}{11}+\dfrac{1}{6}\right)\) \(5.\left(\dfrac{1}{4}+\dfrac{1}{7}+\dfrac{1}{6}+\dfrac{1}{11}\right)\)

_______________________ X ________________________

\(4.\left(\dfrac{1}{3}+\dfrac{1}{13}+\dfrac{1}{11}+\dfrac{1}{6}\right)\) \(9.\left(\dfrac{1}{4}+\dfrac{1}{7}+\dfrac{1}{6}\dfrac{1}{11}\right)\)

= \(\dfrac{2}{4}X\dfrac{5}{9}\)= \(\dfrac{10}{36}\)= \(\dfrac{5}{18}\)

M = 3/4 - 3/5 + 3/7 + 3/11 / 13/4 - 13/5 + 13/7 + 13/11

M = 3.(1/4 - 1/5 + 1/7 + 1/11) / 13.(1/4 - 1/5 + 1/7 + 1/11)

M = 3/13

M = 3/4 - 3/5 + 3/7 + 3/11 / 13/4 - 13/5 + 13/7 + 13/11

M = 3.(1/4 - 1/5 + 1/7 + 1/11) / 13.(1/4 - 1/5 + 1/7 + 1/11)

M = 3/13