1. Use the definition method to remove the absolute value sign according to the meaning of real numbers containing absolute values, that is, |x|=?x(x?0)?c?x?c(c?0), there is |x|c?x?0(c?0)?x?R(c?0)?2. Use the properties of inequalities to remove the absolute value sign and use the properties of inequalities to transform |x|c(c>0) to solve. For example, |ax?b|>c(c>0) can be ax?b >c or ax?b<-c; |ax?b|