[tex]\displaystyle\bf\\\Big[5+2\times2^8+2^{48}:2^{18}\Big]:\Big[5+2^{12}:2^3+\big(2^5\big)^6\Big]=\\\\\\=\frac{5+2\times2^8+2^{48}:2^{18}}{5+2^{12}:2^3+\big(2^5\big)^6}=\\\\\\=\frac{5+2^{1+8}+2^{48-18}}{5+2^{12-3}+2^{5\times6}}=\\\\\\=\frac{5+2^{9}+2^{30}}{5+2^{9}+2^{30}}=\boxed{\bf1}[/tex]
