Question

va rog frumos exercitiu 1

Answer 1

$a)~si~b) \\ \frac{ 2^{2n} + 2^{2n+1}+ 2^{2n+2} }{ 4^{n}+ 4^{n+1}+ 4^{n+2} } = \\ = \frac{ 2^{2n}(1+2+ 2^{2}) }{ 4^{n}(1+4+ 4^{2} )} = \\ = \frac{ 2^{2n}*7 }{ 4^{n}*21 }= \\ = \frac{ 4^{n}*7 }{(4^{n}*7)*3 } = \\ = \frac{1}{3} .$