1、4a³-a=a(4a²-1)=a(2a+1)(2a-1)2、6xy²-9x²y-y³=-y(9x²-6xy+y²)=-y(3x-y)²3、解方程：x-2分之1-x=2-x分之1-（2)(1-x)/(x-2)=-1/(x-2) -2乘以x-2得1-x=-1-2(x-2)1-x=-1-2x...