[tex]\frac{5\cos\alpha-4\sin\alpha}{3\sin\alpha}=-2|*3\sin\alpha\\5\cos\alpha-4\sin\alpha=-6\sin\alpha\\5\cos\alpha=-2\sin\alpha|:\cos\alpha\\5\frac{\cos\alpha}{\cos\alpha}=-2\frac{\sin\alpha}{\cos\alpha}\\5=-2\text{tg }\alpha|:(-2)\\\text{tg }\alpha=-\frac{5}{2}[/tex]