SOLUTION: Find the general term an for the geometric sequence a1= -5, a2= 10 an=

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Question 745099: Find the general term an for the geometric sequence
a1= -5, a2= 10

an=
Found 2 solutions by stanbon, sachi:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the general term an for the geometric sequence
a1= -5, a2= 10
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r = 10/(-5) = -2
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a(n) = (-5)(-2)^(n-1)
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Cheers,
Stan H.
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Answer by sachi(548) About Me  (Show Source):
You can put this solution on YOUR website!
a1= -5, a2= 10
r=the common ratio=a2/a1=10/(-5)=-2
an=a1(r^n-1)/(r-1)=(-5)[(-2)^n-1]/(-2-1)=5[(-2)^n-1]/3