p i ( )x p ( )x p× ( )x p× ( ) ...x × × p ( ) 1x £ 1 2 3 n p 1 ( )x + p 2 ( )x + p 3 ( ) ...x + + p n ( ) 1x = q 1 ( )x + q 2 ( )x + q 3 ( ) ... ( ) 1x + q x = n i å Q = q j j p j q p j j D , i j