what is y=-2log3/5los3-7log2?

y=-2log3 all over 5log3-7log2?

Do you want

$$\\y=\frac{-2log3}{5log3-7log2}\qquad?\\\\
y=\frac{log3^{-2}}{log3^5-log2^7}\\\\
y=\frac{log3^{-2}}{log\frac{3^5}{2^7}}\\\\
$This does not seem to be helping much$$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{log3}}}{\left({\mathtt{5}}{\mathtt{\,\times\,}}{\mathtt{log3}}{\mathtt{\,-\,}}{\mathtt{7}}{\mathtt{\,\times\,}}{\mathtt{log2}}\right)}} = {\mathtt{\,-\,}}{\frac{{\mathtt{2}}{\mathtt{\,\times\,}}{log}_{10}\left({\mathtt{3}}\right)}{{\mathtt{\,-\,}}{\mathtt{7}}{\mathtt{\,\times\,}}{log}_{10}\left({\mathtt{2}}\right){\mathtt{\,\small\textbf+\,}}{\mathtt{5}}{\mathtt{\,\times\,}}{log}_{10}\left({\mathtt{3}}\right)}}$$      that didn't help either

I did it on my casio calc and got -3.427640726

This is an estimate.

$$y=\frac{-2log3}{5log3}-7log2$$

is that your question?

If it is then you can just cancel out the log3 s

If it is not then you need to introduce brackets and post under this one.  

I don't know how to insert -2log3 divided by (5log3-7log2) in the calculator, to get an answer