Answer:
4+3x
It's pretty straight forward, you have the number 4 that is added to the rest of the expression because sum is addition, and the product of 2 numbers is multiplication so it would make 3(x) or 3x, which results in 4+3x.
We have been given a graph of function g(x) which is a transformation of the function 
Now we have to find the equation of g(x)
Usually transformation involves shifting or stretching so we can use the graph to identify the transformation.
First you should check the graph of 
You will notice that it is always above x-axis (equation is x=0). Because x-axis acts as horizontal asymptote.
Now the given graph has asymptote at x=-2
which is just 2 unit down from the original asymptote x=0
so that means we need shift f(x), 2 unit down hence we get:

but that will disturb the y-intercept (0,1)
if we multiply
by 3 again then the y-intercept will remain (0,1)
Hence final equation for g(x) will be:

For this case, the first thing we must do is define variables:
x = number of quarters
y = number of dimes
We now write the system of equations:
x + y = 28
0.25x + 0.10y = 4.05
Solving the system of equations we have:
x = 8.33
y = 19.66
Rounding:
x = 8
y = 20
Answer:
the college student has:
8 quarters
20 dimes
Your equation or notation would be: 12(6+5)