Chú ý ghi đủ yêu cầu đề
\(\frac{x+1}{10}+\frac{x+1}{11}=\frac{x+1}{12}\)
=> \(\frac{x+1}{10}+\frac{x+1}{11}-\frac{x+1}{12}=0\)
⇒ \(\left(x+1\right)\left(\frac{1}{10}+\frac{1}{11}-\frac{1}{12}\right)=0\)
⇒ \(x+1=0\) (do \(\left(\frac{1}{10}+\frac{1}{11}-\frac{1}{12}\right)\ne0\)
=> x = - 1
\(\frac{1}{2}x-\frac{1}{6}x+1=0\)
=> \(x\left(\frac{3}{6}-\frac{1}{6}\right)=-1\)
=> \(\frac{1}{3}x=-1\)
=> \(x=-3\)