Final answer:
To find the number of packages of breadsticks Dirk bought, divide the total number of breadsticks by the number of breadsticks in each package.
Step-by-step explanation:
To find the number of packages of breadsticks Dirk bought, we need to divide the total number of breadsticks by the number of breadsticks in each package. The expression that represents this is:
Number of packages = Total number of breadsticks / Number of breadsticks in each package
In this case, Dirk brought b breadsticks and they are packaged in bags of 4, so the expression would be:
Number of packages = b / 4