Jacob lent a book from the library. He has to pay $9 for the first 5 days and $5 for every subsequent week. Write an expression that will subtract the money from his savings after x weeks from the fifth day.
For the first 5 days, he has to pay $9.
-9 will model this situation.
After the fifth day, he has to pay $5 per week. So, for x weeks, he has to pay $5x.
Therefore, the required expression is -9 - 5x.