If they sold 89 calendars over 4 weeks, the 'equation' would look like (x = average calendars sold over 4 weeks):

If you solve it, you get:

Which is equal to
22.25. Hope this helps!
Answer:
associative property with respect to addition and subtraction
3+[7+(-4)]=(3+7)+(-4)
3+[7-4]=10+(-4)
3+3=10-4
6=6
Step-by-step explanation:
i hope it will help you