goi tong tren la E

E= 42+45+48+....+57

E=(42+57)+(45+54)+(48+51).

E=99+99+99

E=297

mik

mik cung nhan ma

what??????????????????????

hoi vay ma cung hoi a.5+5=10

tan dung thien nhien qua nhieu roi nen phai song hoa hop thoi

anh dep qua hen!

nguoi thap,map nen mac loai vai co hoa van la duong ke soc cung voi mau toi .Mat vai mem,tron thi se tao cho moi nguoi cach nhin tinh te hon ve nguoi do.

cung nhu mon ve thoi. Ta nen phoi hop mau sac doi nghich nhau nhu mau nong va mau lanh vay do.De nhu an com bua vay ma con hoi ho ho ho!