\[y = 25x - 18\]
\[D(y) = R;\ \ \]
\[E(y) = R;\]
\[y = 0:\]
\[25x - 18 = 0\]
\[25x = 18\]
\[x = \frac{18}{25} = \frac{72}{100}\]
\[x = 0,72.\]
\[y > 0\ \ при\ x > 0,72;\]
\[y < 0\ при\ x < 0,72.\]
\[Функция\ возрастает.\]