Im using multiplication for this :p
Since small packages cost him $3.20 to send, and he has to sell 6 of them, i did the equation:
![3.20 * 6 = 19.20](https://img.qammunity.org/2021/formulas/mathematics/high-school/eu4lqoqkpsh66bm1gz8e64y7lse87uw54h.png)
Now he has to send 4 large packages, each the price of $4.70. The equation:
If you want to add them both:
![18.80 + 19.20 = $38](https://img.qammunity.org/2021/formulas/mathematics/high-school/4cnmymnzbtddcv6po14hw4qiunv558c7vf.png)
youre welcome :p