\(\left(\frac{1}{2}\right)^3:2+\left(-\frac{1}{3}\right)^3.2-\left[\left(\frac{7}{11}\right)^{2009}\right]^0\)

\(=\frac{1}{8}:2-\frac{1}{27}.2-1\)

\(=\frac{1}{16}-\frac{2}{27}-1\)

\(=-\frac{437}{432}\) số xấu wá

\(\left(-\frac{1}{2}\right)^3:3+\left(-\frac{1}{3}\right)^{-3}.2-\left(\left(\frac{7}{11}\right)^{2009}\right)^0\)

Đề phải gì không bạn 

giúp mình với

a) Đặt biểu thức trên là A

\(A=\frac{1}{5}-\frac{3}{7}+\frac{5}{9}-\frac{2}{11}+\frac{7}{13}+\frac{2}{11}-\frac{5}{7}+\frac{3}{7}-\frac{1}{5}\)

\(A=\left(\frac{1}{5}-\frac{1}{5}\right)+\left(\frac{-3}{7}+\frac{3}{7}\right)+\left(\frac{-2}{11}+\frac{2}{11}\right)+\frac{5}{9}+\frac{7}{13}-\frac{5}{7}\)

\(A=0+0+0+\frac{5}{9}+\frac{7}{13}-\frac{5}{7}\)

\(A=\frac{128}{117}-\frac{5}{7}\)

\(A=\frac{311}{819}\)

Bài 1: 

\(=\dfrac{-1}{2}+\dfrac{3}{5}-\dfrac{1}{9}+\dfrac{1}{131}+\dfrac{2}{7}+\dfrac{4}{35}-\dfrac{7}{18}\)

\(=\left(-\dfrac{1}{2}-\dfrac{1}{9}-\dfrac{7}{18}\right)+\left(\dfrac{3}{5}+\dfrac{2}{7}+\dfrac{4}{35}\right)+\dfrac{1}{131}\)

\(=\dfrac{-9-2-7}{18}+\dfrac{21+10+4}{35}+\dfrac{1}{131}\)

=1/131

Bài 2:

b: \(B=\dfrac{1}{99}-\left(\dfrac{1}{1\cdot2}+\dfrac{1}{2\cdot3}+...+\dfrac{1}{98\cdot99}\right)\)

\(=\dfrac{1}{99}-\left(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{98}-\dfrac{1}{99}\right)\)

\(=\dfrac{1}{99}-\dfrac{98}{99}=-\dfrac{97}{99}\)