Multiply $\frac{2}{3}$ times $\frac{u}{5}$ by multiplying numerator times numerator and denominator times denominator.
$$\frac{1}{5}-\frac{2u}{3\times 5}$$
Multiply $3$ and $5$ to get $15$.
$$\frac{1}{5}-\frac{2u}{15}$$
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of $5$ and $15$ is $15$. Multiply $\frac{1}{5}$ times $\frac{3}{3}$.
$$\frac{3}{15}-\frac{2u}{15}$$
Since $\frac{3}{15}$ and $\frac{2u}{15}$ have the same denominator, subtract them by subtracting their numerators.
