1. The problem statement, all variables and given/known data let a,b,c be three integers is a divides c and b divides c, then either a divides b or b divides a. if a,b,c,d are real numbers with a<b and c<d, then ac<bd. 2. Relevant equations 3. The attempt at a solution So for part 1 Since a/c and b/c then, c=ak and c=bd for some integers k,d. hence, ak=bd so a/b=d/k where d/k =l for some integer l. so a/b=l... Therefore a/b. end of proof. for part 2) a<b and c<d (given). let a= -5 and b=-4 satisfying a<b and let c=-7 and d=-5 satisfying c<d so then ac = 35 and bd = 20 so 35<20 but this is false therefore ac<bd is false. end of proof. Can Someone please tell me if I have done this correctly?