$$4500 \cdot 1,35^x = 100.000 \Rightarrow 45 \cdot 10^2 \cdot 1,35^x = 10^5 \\ \Rightarrow 45 \cdot 1,35^x=10^3 \Rightarrow 1,35^x=\frac{10^3}{45} \Rightarrow 1,35^x=\frac{200}{9} \Rightarrow x=\log_{1,35}\frac{200}{9} \\ \Rightarrow x=\log_{1,35} 200-\log_{1,35} 9$$