Respostas

2014-04-06T17:16:57-03:00
 \frac{ 3^{2n+1}-9^{n} }{3^{2n}}\\\\ \frac{3^{2n+1}}{3^{2n}} - \frac{9^n}{3^{2n}} \\\\\frac{3^{2n+1}}{3^{2n}} - \frac{9^}{3^{2}} \\\\\\3- \frac{9}{9} \\\\3-1=2
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divisão de potencias de mesma base...mantem a base e subtrai os expoentes..por isso que deu 3