Standard results for an unknown power? FP1
If you just write the series out explicitly it should be obvious.Spoiler:ShowIt's a geometric series. If you know what that is, then really you should have got this; it only requires simply writing out the series.
If you don't know what a geometric series is, then fair enough. You might want to look them up, but I think it would be better to try and derive a formula yourself.
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