51. I checked the comments but I still didn't understand it, sorry :/
54.
(43+45+47+49)=184
They are all odd and they are in consecutive order (one after another)
It is 25 percent because 6 goes into 24 4 times
The same constant value(s)
To find the inverse, switch the variables and solve for f(x).
x = e^f(x) + 6
x - 6 = e^f(x)
f(x) = ln(x-6)
hope this helps :)