CNF-satisfiability problem. (CNF=product of Sum. DNF=Sum of product)

(1) Prove briefly that the DNF-satisfiability (search solution) problem has a polynomial time algorithm and state the time complexity roughly.

(2) It is known that every CNF Boolean expression can be rewritten as a DNF Boolean expression using Distributive law or DeMorgans law. (For example, (X+Y)Z =XZ+YZ) Consider the following algorithm to solve CNF-satisfiability (search solution) problem: Given a CNF Boolean expression, we first transform it into a DNF Boolean expression, then use the method on Part(2) to solve the DNF Boolean expression. This will give a solution to the original CNF Boolean expression. Is this a polynomial time algorithm to solve CNF Boolean expression? Why?