1）x²+16x=0x(x+16)=0x=0或x=-16（2）5x平方-10x=-5x方-2x+1=0(x-1)方=0x1=x2=1（3）x（x-3）+x-3=0(x-3)(x+1)=0x1=3,x2=-1（4）2（x-3）²=9-x²2(x-3)方+（x+3）(x-3)=0(x-3)[2(x-3)+x+3]=0(x-3)(3x-3)=0(x-3)(x-1)=0x1=3或x2=1
