Question

$$\left. \begin{array} { l } { 3 x \geq 15 / \frac { 2 x } { 5 } \leq 4 } \end{array} \right.$$

Solve for x

$x\in [-\frac{5\sqrt{2}}{2},0)\cup [\frac{5\sqrt{2}}{2},\infty)$