1.(x-1)(x-1-2)=0x=1或32.(x+2+3)(x+2-3)=0x=-5或13.9(x-2)²-4(x+1)²=0[3(x-2)+2(x+1)][3(x-2)-2(x+1)=0(5x-4)(x-8)=0x=4/5或84.2(t-1)²+t-1=0(t-1)[2(t-1)+1]=0(t-1)(2t-1)=0t=1或1/2