$\displaystyle \left[ \frac{9}{15},+\infty \right)$\displaystyle \left[ \frac{9}{15},+\infty \right)

$\displaystyle \left(-\infty, \frac{18}{25} \right]$\displaystyle \left(-\infty, \frac{18}{25} \right]

$\displaystyle \left[ \frac{1}{30},+\infty \right)$\displaystyle \left[ \frac{1}{30},+\infty \right)

$\displaystyle \left(-\infty, \frac{9}{5} \right]$\displaystyle \left(-\infty, \frac{9}{5} \right]