[tex] \frac{x}{4} + \frac{3}{5} * \frac{3x}{4} +4260=x\\\\
\frac{x}{4} + \frac{9x}{20}+4260=x ~~~| ~aducem~la ~acelasi~numitor!\\\\
\frac{5x}{20} + \frac{9x}{20}+ \frac{85200}{20}= \frac{20x}{20} \\\\
5x+9x +85200=20x\\\\
14x+85200=20x\\\\
85200=20x-14x\\\\
6x=85200\\\\
x= \frac{85200}{6}\\\\
\boxed{\boxed{\bold{x=14200} }}[/tex]
