能用配方法.原方程变形为：x^-x=72两边都加上 1/4,得x^-x+1/4=72+1/4即 (x-1/2)^=289/4所以 x-1/2=± 17/2故 x1=17/2+1/2=9,x2=-17/2+1/2=-8(不符实际意义,舍去）所以 x=9
能用配方法.原方程变形为：x^-x=72两边都加上 1/4,得x^-x+1/4=72+1/4即 (x-1/2)^=289/4所以 x-1/2=± 17/2故 x1=17/2+1/2=9,x2=-17/2+1/2=-8(不符实际意义,舍去）所以 x=9