How do you add two or more polynomials or equation? How do you store input values to a list or matrix?

eqprompt='Enter Equation (from highest to lowest degree):';
equation=inputdlg(eqprompt);

This is all i got honestly... Basically what i want to do is ask the user to input polynomial equations as many as he likes and then store it to a matrix or list then give him a choice to either add, subtract, multiply, or divide those equations.