Question: 2/5 - 3x/(1 - 4/5) =
1. **State the problem:** Simplify the expression $$\frac{2}{5} - \frac{3x}{1 - \frac{4}{5}}$$.
2. **Simplify the denominator:** Calculate $$1 - \frac{4}{5}$$.
$$1 - \frac{4}{5} = \frac{5}{5} - \frac{4}{5} = \frac{5 - 4}{5} = \frac{1}{5}$$
3. **Rewrite the expression:** Substitute the simplified denominator back into the expression.
$$\frac{2}{5} - \frac{3x}{\frac{1}{5}}$$
4. **Divide by a fraction:** Dividing by $$\frac{1}{5}$$ is the same as multiplying by its reciprocal $$5$$.
$$\frac{2}{5} - 3x \times 5$$
5. **Multiply:**
$$\frac{2}{5} - 15x$$
6. **Final simplified expression:**
$$\boxed{\frac{2}{5} - 15x}$$