cho phương trình x^2 - mx + 2m - 5 = 0 ( m là tham số ). Tìm giá trị của m để   x1 + x2 = 3x1 . x2 
cíu tuii

-he asked me why I had to do that work

-he asked Lan what she was doing

-lan asked me what I would do when I left school

-he asked Lan how she knew his name

-he asked Lan why she hadn't phoned him

-lan asked me when she could see the doctor

-he asked Lan where she was going

-lan asked me where I was going to spend the holiday

-he asked Lan how big the classes were

-lan asked me what sorts of food they served