稍后给你详细过程先得到：(a+3)(a-2)(a-1)=12(a+2)设x=a+1简化得：(x+2)(x-3)(x-2)=12(x+1)(x2-4)(x-3)=12x+12 x3-3x2-4x+12-12x-12=0x(x2-3x-16)=0得x=0或(x-3/2)2=73/4下面不需要写了吧