Math for Information Technology discussion

Prove that sum of an odd integer and an odd integer is an even integer.
2. Let a, b, and c be non zero integers. Prove that if a divides b and a divides c, then a^2 divides the product of b times c.
3. Use induction to prove that the sum of the first n positive odd integers is n^2. (that is, prove that 1 3 5 … (2n-1) = n^2)

must show all work and use appropriate signs. this class uses this book