500+(x115)=2685
the 500 is the money the club is putting towards the trip. the x is the number of club members. the 115 is the cost each member will pay to go on the trip.
subtract 500 from each side leaving you with
(x115)=2185
divide each side by 115
x=19
there are 19 club members going on the trip.
The volume of a pyramid can be calculated as:

Where B is the area of the base and H is the height. We are given V = 60 cubic inches and H = 5 inches. Solving for B:

Substituting:

The area of the base is 36 square inches.
We must choose the option whose area is 36 sq in.
A square of a side length of 6 inches has an area of:

Thus, the correct choice is D.
V(4)=4²-3×4=16-12=4 is the result of substituting t=4 in the function.
18/4 can be simplified into 9/2 or 4 1/2