lớp 6 mới hk số âm bn nha!

nhầm lớp rùi!

\(\Rightarrow\frac{1}{x\left(x+1\right)}-\frac{1}{x}=\frac{1}{2011}\)

\(\Rightarrow\frac{1}{x\left(x+1\right)}-\frac{x+1}{x\left(x+1\right)}=\frac{1}{2011}\)

\(\Rightarrow\frac{1-\left(x+1\right)}{x\left(x+1\right)}=\frac{1}{2011}\)

\(\Rightarrow\frac{-x}{x\left(x+1\right)}=\frac{1}{2011}\)

\(\Rightarrow\frac{-1}{x+1}=\frac{1}{2011}\Rightarrow x+1=-2011\)

\(\Rightarrow x=-2012\)