PLEASE ANSWER QUESTIONS 4 5 and 6

4. [1 point] What rule of inference is used in the following argument? Premises: "If it is rainy, then the pool will be closed. It is rainy. "It is rainy Conclusion: "The pool is closed". a. Hypothetical Syllogism b. Modus Tollens c. Modus Ponens d. Disjunctive Syllogism 5. Let Q(x,y) be the statement x+y=0, n Assume that U is the real numbers. Then xyQ(x,y) is false, but yxQ(x,y) is true. a. True b. False PART 2 (STRUCTURED QUESTIONS) Show all your steps to get full points 6. [4 points] Determine the truth value of each of these statements if the domain for all variables consists of all integers. a) n(n20) b) n(n2=2) c) n(n2n) d) n(n2