\[g(x) = - 13x + 65.\]
\[g(x) = 0:\]
\[- 13x + 65 = 0\]
\[- 13x = - 65\]
\[x = 5.\]
\[g(x) > 0:\]
\[- 13x > - 65\]
\[x < 5.\]
\[g(x) < 0:\]
\[x > 5.\]
\[Функция\ убывающая.\ \]