Question

[Nguyễn Ngọc Ngân An]

2/1 x 3 + 2/3 x 5 +........+ 2/(X - 2) x X = 1994/1995

Answer 1

[Thầy Hùng Olm]

\(1-\dfrac{1}{x}=\dfrac{1994}{1995}\)

\(\dfrac{1}{x}=\dfrac{1}{1995}\)

x= 1995

Answer 2

[Nguyễn Thị Thương Hoài]

\(\dfrac{2}{1\times3}\) + \(\dfrac{2}{3\times5}\) +...+ \(\dfrac{2}{\left(x-2\right)\times x}\) = \(\dfrac{1994}{1995}\)

\(\dfrac{1}{1}\) - \(\dfrac{1}{3}\) + \(\dfrac{1}{3}\) - \(\dfrac{1}{5}\) +...+ \(\dfrac{1}{x-2}-\dfrac{1}{x}\) = \(\dfrac{1994}{1995}\)

1 - \(\dfrac{1}{x}\) = \(\dfrac{1994}{1995}\)

     \(\dfrac{1}{x}\) = 1 - \(\dfrac{1994}{1995}\)

     \(\dfrac{1}{x}\) = \(\dfrac{1}{1995}\)

      \(x\) = 1995