a= (\(\frac{2}{5}\)+\(\frac{2}{9}\)+\(\frac{2}{11}\)\(\times\)\(\frac{5}{7}\)\(+\frac{7}{9}\)\(+\frac{7}{11}\)\()\)

ê làm đc tích cho nha

=0 jnh ban

\(B=\left(\frac{-3}{5}+\frac{4}{9}\right)\div\frac{7}{11}+\left(-\frac{2}{5}+\frac{5}{9}\right)\div\frac{7}{11}\)

\(B=\left(\frac{-3}{5}+\frac{4}{9}\right).\frac{7}{11}+\left(\frac{-2}{5}+\frac{5}{9}\right).\frac{7}{11}\)

\(B=\frac{7}{11}.\left(\frac{-3}{5}+\frac{-2}{5}+\frac{4}{9}+\frac{5}{9}\right)\)

\(B=\frac{7}{11}\left(\frac{-5}{5}+\frac{9}{9}\right)\)

\(B=\frac{7}{11}.\left(-1+1\right)=\frac{7}{11}.0=0\)

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

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

   \(=2+\frac{-7}{13}+\frac{-6}{13}\)

 \(=2+-1\)

 \(=1\)

b) \(\frac{-5}{11}+\left(\frac{2}{3}+\frac{-6}{11}\right)\)

   \(=\frac{-5}{11}+\frac{-6}{11}+\frac{2}{3}\)

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

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

c) \(\frac{5}{9}+\frac{-7}{11}+\frac{9}{29}+\frac{4}{9}+\frac{-4}{11}\)

\(=\frac{5}{9}+\frac{4}{9}+\frac{-7}{11}+\frac{-4}{11}+\frac{9}{29}\)

\(=1+-1+\frac{9}{29}\)

\(=0+\frac{9}{29}\)

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

a)\(\frac{11^4.6-11^5}{11^4-11^5}:\frac{9^8.3-9^9}{9^8.5+9^8.7}\)

\(=1.6:\frac{9^8.3-9^8.9}{9^8.\left(5+7\right)}\)

\(=6:\frac{9^8.\left(3-9\right)}{9^8.12}\)

\(=6:\frac{9^8.\left(-6\right)}{9^8.12}\)

\(=6:\left(-\frac{6}{12}\right)\)

\(=6:\left(-\frac{1}{2}\right)\)

\(=-12\)

b) 3/5 : ( -1/5-1/6)+3/5:(-1/3-16/15) ( mình chuyển về ps luôn )

=3/5: (-11/30) + 3/5 : (-7/5) 

=3/5:[-11/30+(-7/5)]

=3/5:53/30

=18/53

c) (1/2-13/14):5/7-(-2/21+1/7):5/7

= -3/7:5/7-1/21:5/7

=(-3/7-1/21):5/7

=-10/21:5/7

=-2/3

câu b vá c mình làm tắt nha. chúc bạn học tốt

\(=\frac{11}{-5}\cdot\frac{-9}{11}\cdot\frac{15}{-14}\cdot\frac{2}{5}+-\frac{2}{77}\cdot\frac{5}{-3}\)
\(=\frac{9}{5}\cdot-\frac{15}{14}\cdot\frac{2}{5}+\frac{10}{231}\)
\(=-\frac{841}{1155}\)

Giúp mik với mn ơi

1.\(\left(-\frac{6}{5}+\frac{6}{16}-\frac{6}{23}\right):\left(\frac{9}{5}-\frac{9}{16}+\frac{9}{23}\right)\)

\(=6\left(-\frac{1}{5}+\frac{1}{16}-\frac{1}{23}\right):\left(-9\right)\left(\frac{-1}{5}+\frac{1}{16}-\frac{1}{23}\right)\)

\(=6:\left(-9\right)=-\frac{2}{3}\)

2. \(\frac{\frac{3}{7}-\frac{3}{11}+\frac{3}{13}}{\frac{5}{7}-\frac{5}{11}+\frac{5}{13}}+\frac{0.5-\frac{1}{3}+\frac{1}{4}}{-\frac{3}{2}+1-\frac{3}{4}}\)

\(=\frac{3\left(\frac{1}{7}-\frac{1}{11}+\frac{1}{13}\right)}{5\left(\frac{1}{7}-\frac{1}{11}+\frac{1}{13}\right)}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}}{-3\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{4}\right)}\)

\(=\frac{3}{5}-\frac{1}{3}\)

\(=\frac{9}{13}-\frac{5}{15}=\frac{4}{15}\)