[tex]0,75x-5=0,1(6)x \Rightarrow \frac{75x}{100} -5 = \frac{(16-1)x}{90}\Rightarrow \\ \\ \Rightarrow \frac{15x}{20} -5= \frac{15x}{90} \Rightarrow \frac{15x-100}{20}= \frac{5x}{30} \Rightarrow \frac{3\cdot(15x-100) }{60} = \frac{2\cdot5x}{60} \Rightarrow \\ \Rightarrow 45x-300 = 10x \Rightarrow 45x-10x=300 \Rightarrow35x=300\Rightarrow x = \frac{300}{35} \Rightarrow \\ \\ \Rightarrow x = \frac{60}{7} [/tex]
