Well first you need to show the rest of the problems before i can truely help you sorry.
Answer:

Step-by-step explanation:
Since there are 360 degrees in a circle, we can set up the following proportion:

Answer:
A.
Step-by-step explanation:
Answer:
40
Step-by-step explanation:
9a + 9b + 9c = 5
We want 72a
72a/9a = 8 so multiply the first equation by 8
8(9a + 9b + 9c) = 5*8
72a +72b +72c = 40