Bài 1 phần 2 , B = … í ạ
View attachment 108206
\[\begin{align}
& (\frac{1}{2}-1): (\frac{1}{3}-1): (\frac{1}{4}-1): (\frac{1}{5}-1):...: (\frac{1}{100}-1) \\
& =\frac{-1}{2}:\frac{-2}{3}:\frac{-3}{4}:\frac{-4}{5}...:\frac{-99}{100} \\
& =\frac{-1}{2}.\frac{-3}{2}.\frac{-4}{3}.\frac{-5}{4}.....\frac{-100}{99} \\
& =\frac{-1.100}{2.2}=-25 \\
\end{align}\]