hs cat õ tai 2 diem phan biet =>y=0

=>pt<=>x2+2(m-1)x+m+4m-3=0

pt cat õ tai 2 diem phan biet =>(m-1)2-(m+4m-3)>0

<=> m2-7m+4>0

=>m>....  m<.....

ta co x1=x2+2

=> x1-x2=2     =>(x1-x2)2=4    <=>(x1+x2)2 -4x1x2=4

theo viet ta co x1+x2=.....     x1x2=..........

thay vao pt tren giai va ket hop nghiem