\(9^{70}=\left(9^7\right)^{10}=\left(\left(3^2\right)^7\right)^{10}=\left(3^{14}\right)^{10}\)
\(8^{100}=\left(2^3\right)^{100}=\left(\left(2^3\right)^{10}\right)^{10}=\left(2^{30}\right)^{10}\)
\(2^{30}>\left(2^4\right)^7>\left(3^2\right)^7=3^{14}\)
\(\Rightarrow2^{30}>3^{14}\Leftrightarrow9^{70}< 8^{100}\)
\(9^{70}=\left(9^7\right)^{10}=4782969^{10}\)
\(8^{100}=\left(8^{10}\right)^{10}=1073741824^{10}\)
\(4782969< 1073741824\)
\(\Rightarrow9^{70}< 8^{100}\)
ta có: 9 mũ 70= 4782969 mũ 10
8 mũ 100=1073741824 mũ10
vì 1073741824>4782969 nên 8 mũ 100 >9 mũ 70
