2x（x-1）-3x=0,x[2(X-1)-3]=x(2x-5)=0 x=0或 x=5/2（3-t）方+t方=9,(t-3)^2+t^2-9=0 (t-3)^2+(t+3)(t-3)=0 (t-3)(2t)=0 t=0或t=3x方-m（2x-m）=x-m ,x^2-2mx+m^2-x+m=0 x^2-2mx+m^2-(x-m)=0 (x-m)^2-（x-m)=0 (x-m)...