Well, function is already written in "function notation" though not explicitly which I assume is "function notation".
Explicit notation for this function is:

Hope this helps.
Consider that the three consecutive integers are:
least integer = n
middle integer = n + 1
greatest integer = n + 2
THe expression "three consecutive integers is 12 less than 4 times the middle integer" can be written as follow:
n + (n + 1) + (n + 2) = 4(n +1) - 12
In order to find the numbers, proceed as follow:
n + (n + 1) + (n + 2) = 4(n +1) - 12 cancel parenthesis
n + n + 1 + n + 2 = 4n + 4 - 12 simplify like terms
3n + 3 = 4n - 8 subtract 4n and 3 both sides
3n - 4n = - 8 - 3
-n = -11
n = 11
Hence, the three consecutive integers are:
n = 11
n + 1 = 12
n + 2 = 13
So 4.75 times 42= 199.5 so take 240-199.5= 40.5 so he is correct
To get the percentage of how much Nick owns, we have to divide the part (500) by the whole (100,000) then multiply the product by 100.
500 / 100,000 = 0.005
0.005 × 100 = .5%
Nick is entitled to $2,500,000 × .5% = $12,500