If i remember correctly i think you just cross multiply <span />
Let the first term be a(0). Then the formula for a(n) is a(0)-18(n-1).
Check: What's the first term? Let n = 1: a(1) = a(0)-18(1-1) = a(0) (correct)
What's the second term? Let -n =2: a(2) = a(0)-18(2-1) = a(0) - 18
and so on.
3 piles of 9 pictures is 27. Because 9*3=27. So, your answer should say "Alise had 27 pictures in all because 9*3=27"
Answer:

Step-by-step explanation:
By definition if two events are mutually exclusive then they are disjoint events, that is, they can not occur at the same time.
In general terms we say that events are mutually exclusive, then:

In this case we have that

But A and B are mutually exclusive events, then 
11.8/2 = 5.9
5.9 squared is <span>34.81
34.81 multiplied by pi is </span>109.358840271