1,Cho phan so\(\frac{3}{7}\)Cong them vao tu so va mau so cung 1 so tu nhien ta duoc phan so bang \(\frac{7}{9}\). Tim so do
2, Cho phan so \(\frac{5}{11}\). Cong ca tu va mau so voi cung 1 so tu nhien vao ta duoc phan so bang \(\frac{13}{16}\). Tim so do