\[(0;4):\]
\[4 = k \bullet 0 + b\]
\[b = 4 \Longrightarrow y = kx + 4.\]
\[( - 2;0):\]
\[0 = k( - 2) + 4\]
\[2k = 4\]
\[k = 2 \Longrightarrow y = 2x + 4.\]
\[Ответ:y = 2x + 4.\]