Aprism is created using 2 regular pentagons as bases. the apothem of each pentagon is 2.8 centimeters.

which expression represents the volume of the prism, in cubic centimeters?

9x2 + 7x
14x2 + 7x
16x2 + 14x
28x2 + 14x

The volume of any solid shape takes a general equation of base times its height. The base referred to here is the area of one base of the prism. So, first, we determine the area of the pentagon. The equation is:

Area=1/2*apothem*perimeter -->perimeter is the sum of all side lengths
Area = 1/2*2.8*(5*x)   ---> perimeter is 5x because a regular pentagon has 5 equal sides
Area = 7x square units

Then, we use the formula for volume 
Volume=Area of base x height
Volume = 7x (2x+1)
Volume = 14x^2 + 7x cubic units