\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
=> \(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}-\frac{x+1}{13}-\frac{x+1}{14}=0\)
= (x + 1) (1/10 + 1/11 + 1/12 - 1/13 - 1/14 ) = 0
vi (1/10 + 1/11 + 1/12 - 1/13 - 1/14 ) \(\ne\)0
=> x + 1 = 0
=> x = - 1