[tex]\displaystyle\bf\\b)\\\\5^{30}~~si~~7^{20}\\\\Presupun~ca~se~cere~sa~comparam~cele~2~numere.\\\\5^{3\times10}~~si~~7^{2\times10}\\\\\Big(5^3\Big)^{10}~~si~~\Big(7^2\Big)^{10}\\\\125^{10}>49^{10}\\\\\implies~5^{30}>7^{20}[/tex]
