please do all the questions!

5. Proof methods For each claim below, prove or disprove the claim. To prove a claim, you need to provide a formal proof. (a) (5 points) n0,nZ,n2+n+17 is prime. (b) (5 points) For all rational numbers a and b,a/b is also rational. 5. Proof methods For each claim below, prove or disprove the claim. To prove a claim, you need to provide a formal proof. (a) (5 points) n0,nZ,n2+n+17 is prime. (b) (5 points) For all rational numbers a and b,a/b is also rational