1. **State the problem:** Kirstie charges $18 for the first hour and $14 for each additional hour. The total charge $C$ is given by the formula $$C = 18 + 14(h - 1)$$ where $h$ is the number of hours worked. We know Kirstie earned $46, so we need to find $h$. 2. **Write the equation with the given charge:** $$46 = 18 + 14(h - 1)$$ 3. **Subtract 18 from both sides to isolate the term with $h$:** $$46 - 18 = 14(h - 1)$$ $$28 = 14(h - 1)$$ 4. **Divide both sides by 14 to solve for $(h - 1)$:** $$\frac{28}{\cancel{14}} = \frac{14(h - 1)}{\cancel{14}}$$ $$2 = h - 1$$ 5. **Add 1 to both sides to find $h$:** $$2 + 1 = h$$ $$3 = h$$ **Answer:** Kirstie worked for 3 hours.