1) Mot hinh chu nhat co chu vi la 320 cm . Biet neu viet them chu so 1 vao ben trai so do chieu rong thi duoc so do chieu dai . Tim dien tich cua hinh chu nhat ?
2) Viet cac phan so sau day thanh tong 3 phan so sao cho moi phan so co tu so la 1 , mau so khac nhau
a) 11/26 ; b) 7/8