Answer
$$\frac{x}{10}$$
Work Step by Step
A common denominator of $5$ and $2$ is $10$, so
$$\frac{3x}{5}-\frac{x}{2}=\bigg(\frac{3x}{5}\bigg)\bigg(\frac{2}{2}\bigg)-\bigg(\frac{x}{2}\bigg)\bigg(\frac{5}{5}\bigg)=\frac{6x}{10}-\frac{5x}{10}=\frac{x}{10}.$$