Cube Root Expression 1305F0
1. **State the problem:** Evaluate the expression $$\sqrt[3]{3k} + 5k$$ when $$k = -72$$.
2. **Recall the formula and rules:** The cube root of a number $$a$$ is a value $$b$$ such that $$b^3 = a$$. Also, substitution means replacing $$k$$ with $$-72$$ in the expression.
3. **Substitute $$k = -72$$ into the expression:**
$$\sqrt[3]{3(-72)} + 5(-72)$$
4. **Simplify inside the cube root:**
$$3 \times (-72) = -216$$
So the expression becomes:
$$\sqrt[3]{-216} + (-360)$$
5. **Evaluate the cube root:**
Since $$(-6)^3 = -216$$, we have:
$$\sqrt[3]{-216} = -6$$
6. **Calculate the entire expression:**
$$-6 + (-360) = -6 - 360 = -366$$
**Final answer:** $$-366$$