I am confuse all 3 how to do that

1. (2 pts. each) Does 17 divide each of these numbers? Why or why not? a) 68 b)84 ) 357 d) 1001 2. (5 pts.) Show that if a,b, , and d are integers, where a # 0, such that a | and b | d, then ab | cd. 3. (5 pts.) Prove that if a and b are integers and a divides b, then a is odd or b is even