\[4y^{2} + my - 5 = 0\]
\[D = b^{2} - 4ac =\]
\[= m^{2} - 4 \cdot 4 \cdot ( - 5) =\]
\[= m^{2} + 80 > 0\]
\[D > 0 \Longrightarrow 2\ корня.\]