Answer:
i think it is A the first option
Step-by-step explanation:
Total Cost in a day is

. Profit function is

. And the revenue function is

. In a day, bookstore must sell at least 15 books, because of 6n-90=0, in order to make profit.
Answer:
-10
Step-by-step explanation:
Answer: Top right corner (northeast corner)
Angle IAE = Angle DAH
These two angles are vertical angles as shown in the diagram below. Vertical angles are always congruent.
Answer:
d
Step-by-step explanation:
7x3=21
18x3=54