For a field trip, 4 chaperones and needed for every 18 students. how many chaperones are needed if there are 81 students on the trip?

Two angles are complementary. the large angle is 36 more than the smaller angle. what is the measure of the large angle?

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same