We have
[tex]\log (5x)+\log (7x)-\log (2x)-\log (4x)[/tex]We will use the next properties
[tex]\log (a)+\log (b)=\log (ab)[/tex][tex]\log (a)-\log (b)=\log (\frac{a}{b})[/tex]Then we apply the properties
Here we use the first property two simplify the first two terms
[tex]\begin{gathered} \log (5x\cdot7x)-\log (2x)-\log (4x) \\ \log (35x^2)-\log (2x)-\log (4x) \\ \end{gathered}[/tex]Here we use the second property to simplify the first three terms
[tex]\begin{gathered} \log (\frac{35x^2}{2x})-\log (4x) \\ \log (\frac{35x}{2})-\log (4x) \end{gathered}[/tex]Here we use the second property to simplify the whole expression
[tex]\log (\frac{\frac{35x}{2}}{4x})=\log (\frac{35}{8})[/tex]ANSWER
log(35/8)