Thank youHave you considered [math]\dfrac{2^{n}+4^{n}}{6^{n}} = \dfrac{2^{n}}{6^{n}}+\dfrac{4^{n}}{6^{n}}[/math]?
thank youIn response #2, your problem was reduced to sum of two geometric series. What are the equations for the sum of a geometric series?
It seems that you got a negative number for the answer (-4.5). That is incorrect. Check your formulae again!