For each of the following statements (i. and ii.), either prove it to be true (for full credit you must use variable representation -- not just show it to be true for a few specific numbers!) or prove it to be false by counterexample. Hint: try using proof by contrapositive for problem ii. i. The sum of two even integers and one odd integer must be odd. ii. If 2x+3x+3 is even, then x must be odd (assume x is an integer).