Решите уравнение: (14y+21)(1.8-0.3y)=0.

\[(14y + 21) \cdot (1,8 - 0,3y) = 0\]

\[14y + 21 = 0\ \ \ или\ \ \ 1,8 - 0,3y = 0\]

\[14y = - 21\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0,3y = 1,8\]

\[\ \ \ \ \ y = - \frac{21}{14}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ y = \frac{18}{3}\]

\[\ \ \ \ \ y = - 1,5\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ y = 6\]

\[Ответ:\ y = - 1,5;y = 6.\]