(4274)2= (\frac{4^2}{7^4})^2= (7442)2=
(4274)2=42×274×2=4478 (\frac{4^2}{7^4})^2=\frac{4^{2\times2}}{7^{4\times2}}=\frac{4^4}{7^8} (7442)2=74×242×2=7844
4478 \frac{4^4}{7^8} 7844