5. For each of the statements below state whether it is True or False. If True then give a proof. If False then explain why, e.g., by giving a counterexample. (a) The sum of the squares of any two rational numbers is a rational number (b) For all positive x R, if x is irrational then z is irrational. (c) For all z, yeR, if x and y are irrational then x2 + y is irrational. (d) log10(2) is irrational