Find the rule and complete the pyramid.
( )
(-6) ( )
( ) ( ) ( 6 )
( -1 ) ( ) ( 1 ) ( )
( 4 ) ( 5 ) ( 2 ) ( 1 ) ( 6 )

                   (10)

             (6)         (-4)

        (-4)      (2)      (6)

   (-1)      (3)       (1)       (-5)

(4)     (5)       (2)      (1)      (6)

The pattern is the number to the left of the other number is theproduct of the number on top of them and the one to the right of it

EX.    (-1)

     (4)       (5)

5+(-1)= 4