Can someone explain to me how to solve problems like this? Thanks!

Step-by-step explanation:

In this problem, you are adding 2 functions. To do this, simply take the 2 different rules for each function and add them together. This looks like . Then, to get the final answer remove the parentheses and add like terms. The terms and are like while 5 and 4 are also like. If you add and you get and 5+4 is 9. Therefore, the final answer is

she would want to sell 10 full-year subscriptions and at least 9 half-year subscriptions to get a total of at least $300. 

i hope this answer you! if you have any further questions or concerns, feel free to ask! : )

step-by-step explanation:

mark brainliest!

b). 4320 have a nice day