Exponential functions are related to logarithmic functions in that they are inverse functions. Exponential functions move quickly up towards a [y] infinity, bounded by a vertical asymptote (aka limit), whereas logarithmic functions start quick but then taper out towards an [x] infinity, bounded by a horizontal asymptote (aka limit).
If we use the natural logarithm (ln) as an example, the constant "e" is the base of ln, such that:
ln(x) = y, which is really stating that the base (assumed "e" even though not shown), that:

if we try to solve for y in this form it's nearly impossible, that's why we stick with ln(x) = y
but to find the inverse of the form:

switch the x and y, then solve for y:

So the exponential function is the inverse of the logarithmic one, f(x) = ln x
For the fish bowl the first answer is correct.
(1/2)(4/3)(22/7)(12^3)
For the second problem
(1/3)(3.14)(6^2)(10) - (4/3)(3.14)(1.5^3)
The second answer.
Answer: Lower left corner
A piecewise function is basically a combination of other functions to make one single function. We can break up the given piecewise function into two parts:
f(x) = x-4
OR
f(x) = -2x
The f(x) will change depending on what x happens to be. If x is 0 or smaller, then we go with f(x) = x-4. Otherwise, if x is larger than 0, then we opt for f(x) = -2x.
To graph this, we basically graph y = x-4 and y = -2x together on the same coordinate system. We only graph y = x-4 if x is 0 or smaller. Likewise, we graph y = -2x when x > 0. This results in the graph shown in the lower left corner of your four answer choices.
Note: the closed circle means "include this point as part of the graph". The open circle means "exclude this point as part of the graph". So this is why the upper right corner is very close but not quite the answer we want.