need solution for 1c)

Answer the following questions. Explain your reasoning: a) using the truth table, show that the following statement is a tautology. [4 marks] q((pq)(rp)) b) Without using the truth table, show that the following statement is true: [4 marks] (qp)rp(qr) c) Negate the following statement: [4 marks] x:P(x)[x:(Q(x)R(x)]