2. (5 points) Use the truth table to prove or disprove -(p) =p1-9. 3. (5 points) Suppose P(x,y) means "x * y = y*x", where x and y are real numbers. Determine the truth value for each of the following statements. (a). V x 3 y P(x,y). (b). By V P(x,y)