1. **State the problem:** Kevin earns a base salary of 300 per week plus a 5% commission on his total sales. We need to find his total earnings for sales of 1975 and for a general sales amount $x$. 2. **Formula:** Total earnings $E$ can be calculated as: $$E = \text{base salary} + \text{commission} = 300 + 0.05 \times \text{sales}$$ 3. **Calculate earnings for sales of 1975:** $$E = 300 + 0.05 \times 1975$$ $$E = 300 + 98.75$$ $$E = 398.75$$ 4. **Calculate earnings for sales of $x$:** $$E = 300 + 0.05x$$ 5. **Explanation:** Kevin always earns 300 regardless of sales. The commission is 5% of sales, so for any sales amount $x$, multiply by 0.05 and add 300 to get total earnings. **Final answers:** - For sales of 1975, Kevin makes $398.75$ - For sales of $x$, Kevin makes $300 + 0.05x$