Ответ: [tex]\frac{3\sin6\alpha}{5\cos3\alpha}=\frac{6\sin3\alpha\cos3\alpha}{5\cos3\alpha}=\frac65\sin3\alpha\\\sin3\alpha=-0,1\\\frac56\sin3\alpha=\frac56\cdot\left(-\frac1{10}ight)=-\frac5{60}=-\frac1{12}[/tex]