Found out 5 - 1/2 returned -9/2. Now properly returns 9/2.
Got rid of Log prints, splitInput prints, rpnInput prints, and updated
the menu to reflect the project feedback comment:

"After every operation is dumps you back to the main screen, but it
doesn't reprint the menu choices, so it's difficult to remember what to
choose."

Menu should now print the options everytime.
I have conquered FOIL.
Fixed a subtraction bug.
added same exponent NthRoot adding
Got rid of print out.
Update Add.cpp
Update Add.cpp
Expression add fix.
Update Add.cpp
Fixed an expression adding bug.
Update Subtract.cpp
Did something somewhere.