The expression 224-4x² calculates the surface area of a box (measured in square inches) when the box is made with a square cutout of side length x (measured in inches) from a 14" by 16" sheet of paper. Let g be a function that takes as its input the length of the side of the square cutout (measured in inches) and outputs the surface area of the corresponding box (measured in square inches).
a. What does the expression g(1.5) - g(0.5) represent in this context? What is its value?
b. What does the expression g(6.25) - 8(2.1) represent in this context? What is its value?