Which to factors of 28 add up to 18 full workings?

To find factors of 28 that add up to 18, we first list the factors of 28: 1, 2, 4, 7, 14, and 28. We then check pairs of these factors to see which add up to 18. The only pair that meets this criterion is 14 and 4, since 14 + 4 = 18. Thus, the factors of 28 that add up to 18 are 14 and 4.