2*21 = 42
They are: 2*7*3 = 42
42 - 22 = 16 - 4 = 12
7 x 2 x 3 = 42
42 - 32 = 7
2*21 = 42
6x7
They are: 2*7*3 = 42
42 - 22 = 16 - 4 = 12
32
7 x 2 x 3 = 42
42
-31
6 / 7 2 / 21 3 / 14 1 / 42
They are: 6 and -7
42 - 32 = 7
1 and 42 are one pair. 7 and 6 are another along with 21 and 2