[tex]\displaystyle\bf\\\frac{ log_{2}45 - log_{2}5 }{ log_{2}3 }=\frac{ log_{2}\dfrac{45}{5}}{ log_{2}3 }=\frac{ log_{2}9}{log_{2}3}=\frac{ log_{2}3^2}{log_{2}3}=\frac{ 2\times log_{2}3}{log_{2}3}=2\\\\\\Se~simplifica~fractia~cu~~log_{2}3~~si~ramane~2.[/tex]