sorry for the incovinience lol im still new. the error was:
error: prototype for 'int Fraction::setNum()' does not match any in class 'Fraction'
int Fraction::setNum(){ and
error: candidate is: void Fraction::setNum(int)
void setNum(int n);
You have declared a "setter" with one argument and (correctly) returning nothing: void setNum(int n);
but "started" writing one with no arguments and (unnecessarily) claiming to return an int: int Fraction::setNum()
They don't match.
After that, you are calling a lot of functions that you have yet to write the content of.
A better way to initialise an object of a class like this is through its constructor.