BAI 9:
a.400+500+8/100 b.6,72+24,58
BAI 10: mot o to trong 3 gio dau,moi gio chay duoc 36km,trong 5 gio sau,moi gio gio chay duoc 35km.hoi trung binh moi gio o to chay duoc bao nhieu km ?
moi nguoi giai giup minh nha cam on moi nguoi nhieu,ghi ro cach lam ra nhe