the difference between 7th and 5th terms is 192
---> ar^6 - ar^4 = 192
ar^4(r^2 - 1) = 192 **
the difference between 15th and 3rd terms is 48
---> ar^14 - ar^2 = 48
ar^2(r^12 - 1) = 48 ***
divide ** by ***
r^2(r^2 - 1)/(r^12 - 1) = 4 ****
r^4 - r^2 = 4r^12 - 4
4r^12 - r^4 + r^2 - 4 = 0
clearly, by inspection, r = ±1 would be a solution to this last equation , but not in ** or ***
Something is awry here, did you really mean "difference" ?
in geometric prograssion the difference between 7th and 5th terms is 192 and the difference between 15th and 3rd terms is 48. find the common ratio
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