Integer Proofs by Contradiction - Assume that n is a positive integer. Use the proof by contradiction method to prove:
(a) If 7n + 4 is an even integer, then n is an even integer.
(b) Prove: n is an even integer iff 7n + 4 i ...
Equivalence Relation - Relation S is defined as followed:
xSy iff y-x is an integer (x,y € R) where R=all real numbers
a) prove that S is an equivalence relation on R
b) Which real numbers belong to [-17]?
Irreducible polynomial - Prove that X^n-1+X^n-2+........+X+1 is irreducible over Z iff n is prime.