Answer:
a) 18 in x 18 in x 18 in
b) 
Step-by-step explanation:
a) Let's call 's' the side of the square base and 'h' the height of the solid.
The surface area is given by the equation:

The volume of the solid is given by the equation:

From the volume equation, we have that:

Then, using this value of h in the surface area equation, we have:


To find the side length that gives the minimum surface area, we can find where the derivative of S in relation to s is zero:





The height of the solid is:

b) The minimum surface area is:


The answer to the question above as to which system of equations can be used to model the situation of Graham and Hunter when a cable lifts Graham into the air at a speed of 1.5 ft/s and Hunter throws the ball from a position of 5 ft. above the ground with an initial velocity of 24 ft/s. the equation will be : H = 18t + 1.5t - 16t ^ 2
H = 5 + 24t - 16t ^ 2
The simplest way to do this is to set up equivalent fractions. So, you'd do:

=

and then solve for x.
x=52
The answer is
round cake - 82.42 in²
rectangular cake - 114 in²
Round cake:
d = 7 in
r = d/2 = 7 in / 2 = 3.5 in
h = 2 in
The surface are of a cylinder is:
A = 2πr² + 2πrh
The surface are of the round cake (which is actually a cylindrical cake) excluding the bottom is:
A = 2πr² + 2πrh - πr²
A = πr² + 2πrh
A = 3.14 * 3.5² + 2 * 3.14 * 3.5 * 2
= 38.46 + 43.96
= 82.42 in²
Rectangular cake:
w = 6 in
l = 9 in
h = 2 in
The surface are of a rectangle is:
A = 2wl + 2wh + 2lh
The surface are of the rectangular cake excluding the bottom is:
A = 2wl + 2wh + 2lh - wl
A = wl + 2wh + 2lh
A = 6 * 9 + 2 * 6 * 2 + 2 * 9 * 2
= 54 + 24 + 36
= 114 in²