( 6 x 9 ) + ( 7 x 9) = (6 + 7) x 9
( 4 x 90) + 67 = 67 + ( 4 x 90)
8 + ( 9 + 13) = (9 + 13) + 8
99 = 99 x 1
6 + ( 9 = a) = (6 +9) +a
4 ( 2 + 8 ) = ( 4 x 2) + ( a x 8)
5a + 0 = 5a
1 x ( 2 x 3) = (1 x 2 ) x 3
5 x 6 = 6 x 5
35 x 1 = 35
8 + 0 = 8
6 + 8 = 8 + 6
g x ( h x i) = (g x h) x i
f = 0 + f
( 5 x k) + (6 x k) = (5 + 6) x k
(a + b) + c = a + (b + c)
a ( b + c) = (a x b) + (a x c)
9x = 1 x 9x
