\(\frac{1+3^2+3^4+3^6}{1+3+3^2+3^3+3^4+3^5+3^6+3^7}\)
<=> \(\frac{1+3^2+3^4+3^6}{1+3+3^2+3^6+3+3^3+3^5+3^7}\)
<=> \(\frac{1+3^2+3^4+3^6}{1+3^2+3^4+3^6+3\left(1+3^2+3^4+3^6\right)}\)
<=> \(\frac{1+3^2+3^4+3^6}{4\left(1+3^2+3^4+3^6\right)}\)
<=> \(\frac{1}{4}\)