Найдите значение дроби $$rac{3x^2-12xy}{xy-4y^2}$$ при $$x=6$$, $$y=-10$$

$$rac{3x^2-12xy}{xy-4y^2} = rac{3x(x-4y)}{y(x-4y)} = rac{3x}{y}$$

$$rac{3 cdot 6}{-10} = rac{18}{-10} = -1,8$$