A^3=5 b^3=4 Find value of (ab^2)^-3

I seem to get 400 every time.
(ab)^(2*-3)= ab^-6 = -5*-5*-4*-4=400

Find the area of a trapezoid with bases 14 cm and 18 cm and height 10 cm. 160 cm2 140 cm2 180 cm2 126 cm2

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

Ahome improvement store rents it’s delivery truck for $19 for the first 75 minutes and $4.75 for each additional 1/4 hour. if a customer rented the truck at 11: 10 am and returned the truck at 1: 40 pm the same day, what would his rental cost be?