(1)(x+2)(x-1)=0 x=-2,x=1 (2)(x-2)(x-2)=2 x=2+根号下2,x=2-根号下2 (3)4xx-4x-3=0 (2x-3)(2x+1)=0 x=3/2,x=-1/2 (4)3xx-9x=2xx-2 xx-9x+81/4=-2+81/4 (x-9/2)(x-9/2)=73/4 x=9/2+根号下73/4,x=9/2-根号下73/4