Answer:
14. A. Commutative Property of Addition.
15. D. k=54
Step-by-step explanation:
6 + 9 = 9 + 6 is an example of the Commutative Property of Addition so that is your answer.
k + (-12) = 42. What you do is add the 12 to both sides to get your answer.
k=54 is your answer.
