For this case we have:
way 1:
Common factor 3 in the expression:
[tex]12-3 = 3 (4-1)
12-3 = 3 (3)
12-3 = 3 (9)[/tex]
Way 2:
Write the number 12 as the sum of 4 times 3:
[tex]12-3 = (3 + 3 + 3 + 3) - 3
[/tex]
Then, for associative property:
[tex]12-3 = 3 + 3 + 3 + (3 - 3)
12-3 = 3 + 3 + 3 + (0)
12-3 = 3 + 3 + 3
12-3 = 9[/tex]
