Question 82553
Write the equation of the arithmetic sequence defined by a1 = 3 and a4 = 0. 
a(4)=a(1)+d(4-1)
0 = 3 + 3d
d = -1
EQUATION:
a(n)=3 + d(n-1)
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What is the common ratio of the sequence?
-2, 2, -2, 2, ... 
common ratio = -1
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What is the explicit formula for the sequence? 
3, 6, 12, 24, ... 
a. an = 3*2^(n-1) 
b. an = 2*3^(n-1) 
c. an = 3*-2^(n-1) 
d. an = 3^(n-1) 

Answer: "a"

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Cheers,
Stan H.