28 + 12 = 40
12 + 28 + 24 = 64
43
4 + 8 + 12 + 16 + 14 + 28 + 37 = 119
16+12=28
58
28=8x+12-7x 28=8x-7x+12 28=x+12 28-12=x+12-12 16=x
12(8a + 28) + 2a + 5 84a + 336 + 2a + 5 86a + 341
40
28
-40 + 12 = -28
6x2=12 2x-28=?
1 + 2 + 3 + 4 + 6 + 7 + 12 + 14 + 21 + 28 + 42 = 140