Question: User: \left(-\dfrac{2}5\right)^2 =
1. **State the problem:** Calculate the value of $$\left(-\dfrac{2}{5}\right)^2$$.
2. **Recall the rule:** When squaring a fraction, square both the numerator and the denominator separately.
3. **Apply the formula:**
$$\left(-\dfrac{2}{5}\right)^2 = \dfrac{(-2)^2}{5^2}$$
4. **Calculate numerator and denominator:**
$$(-2)^2 = (-2) \times (-2) = 4$$
$$5^2 = 5 \times 5 = 25$$
5. **Write the fraction:**
$$\dfrac{4}{25}$$
6. **Final answer:**
$$\left(-\dfrac{2}{5}\right)^2 = \dfrac{4}{25}$$