判别式△=(m-1)²-4m(m-2)=m²-2m+1-4m²+8m=-3m²+6m+1=-3m²+6m-3+4=-3(m-1)²+41/4则-3/4所以0<=(m-1)²<1-3<-3(m-1)²<=01<-3(m-1)²+1<=4即△>0所以有两个不同的实数解