Answer: 

<u>Step-by-step explanation:</u>
a) This is an arithmetic sequence where 3 is added to the previous term.
48 + 3 = 51
51 + 3 = 54
54 + 3 = 57
The recursive formula for this sequence is:
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b) This is a geometric sequence where 2.5 is multiplied to the previous term.
100(2.5) = 250
250 (2.5) = 625
625(2.5) = 1562.5
The recursive formula for this sequence is: 
15/20 = 0.75
Each of the gift boxes will get 3/4 yard of ribbon. (.75)
Answer: The area of Rhode Island is about 1,212 square miles
(-3)^2 = 9
-3^2 = -9
Hope this helps!
No because 7/9= 0.777777777789 and 8/9= 0.888888888888889