By definition of the binomial coefficient,

so we have

as required.
Answer:
|x-3|-5
Step-by-step explanation:
f(x) = |x|
These lines are lines of absolute value equations. g(x) is shifted 3 units left so we subtract 3 from within the bars, and shifted down 5 units so we subtract 5 from the absolute value which leaves us with |x-3|-5
Take the derivative:
g’(x) = 12x^3 - 24x^2
Set equal to zero and solve:
0 = 12x^3 - 24x^2
0 = 12x^2 (x - 2)
x = 0 or x = 2
Plug back into original
g(0) = 3(0^4) - 8(0^3)
g(0) = 0 - 0
g(0) = 0
g(2) = 3(2^2) - 8(2^3)
g(2) = 3(4) - 8(8)
g(2) = 12 - 64
g(2) = -52
There is an absolute max at (0,0) or when x = 0

Total amount of Brian paid is $48.30.
Hope this helps. - M