For the first, divide each term on the top by 3 and you'll get the answer.
For the second, isolate p first:
a = 5(p - q)
a/5 = p - q
a/5 + q = p
Then multiply by 10 since that's what the question is asking for:
10(a/5 + q) = 10p
2a + 10q = 10p
2(a + 5q) = 10p