[tex]\displaystyle\bf\\8)\\\\\Big(9\Big)^{11}=\Big(3^2\Big)^{11}=3^{2\times11}=\Big(3^{11}\Big)^{2}=pp\\\\\\10)\\\\Comparam~numerele:~~~10^{30}~si~999^{10}\\\\10^{30}=10^{3\times10}=\Big(10^3\Big)^{10}=1000^{10}\\\\1000^{10} > 999^{10}~deoarece~1000>999\\\\\implies~10^{30}~>~999^{10}[/tex]