Bai 7:Co hai soi day,soi thu nhat dai hon soi thu hai 54m.Neu cat di 1200cm o moi soi thi phan con lai cua soi thu nhat gap 4 phan con lai cua soi day thu hai.Hoi moi soi day dai bao nhieu m?
moi nguoi ghi ro loi giai ra nhe hihi cam on moi nguoi nhieu