Question

Suppose we are given two functions, say r(x) and s(x).
a) Is it true that r(x) + s(x) = s(x) + r(x) for all values of x? Why or why not?
b) Is it true that r(x) s(x) = s(x) r(x) for all values of x? Why or why not?
c) Is it true that r(0) = 0? Why or why not?