\[2x^{2} + 5x = 0\]
\[x(2x + 5) = 0\]
\[x = 0\ \ \ \ \ \ \ \ \ \ \ 2x + 5 = 0\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x = - 2,5\]
\[Ответ:0;\ - 2,5.\]