giai bai toan nang cao lop : hai nguoi ban di mua hoa tet , tong so tien cua hai ban la 79 000 dong khi nguoi thu 1 mua het 5\6 so tien cua minh va nguoi thu 2 mua het 6\7 so tien cua minh thi nguoi thu con lai nhieu hon nguoi thu nhat 2 000 dong . hoi a moi nguoi co bao nhieu tien b moi nguoi tieu het bao nhieu tien