SOLUTION: x+3, x-15, 24 are the first 3 terms to a geometric sequence, find the values of x.

Algebra ->  Sequences-and-series -> SOLUTION: x+3, x-15, 24 are the first 3 terms to a geometric sequence, find the values of x.      Log On


   

Question 754041: x+3, x-15, 24 are the first 3 terms to a geometric sequence, find the values of x.
Answer by reviewermath(1029) About Me  (Show Source):
You can put this solution on YOUR website!
Q:
x+3, x-15, 24 are the first 3 terms to a geometric sequence, find the values of x.
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A:
Common ratio, r = %28x+-+15%29%2F%28x+%2B+3%29 = 24%2F%28x+-+15%29, cross-multiply
%28x+-+15%29%5E2 = 24%28x+%2B+3%29
x%5E2+-+30x+%2B+225 = 24x+%2B+72
x%5E2+-+54x+%2B+153+=++0
%28x+-+51%29%28x+-+3%29+=+0
x - 51 = 0 or x - 3 = 0
x = highlight%2851%29 OR highlight%283%29