Click and drag the given steps (in the right) to their corresponding step names (in the left) to prove that if a, b, c and d are integers, where a and b #0, such that a c and b d, then ab cd cd = (as)(b) = ab(s). It follows that abl od. ad = (cs)(bt) = cb(st). It follows that ab 1 od. Therefore al cand bI d, there are integers s and t such that a = cs and b = dt. al cand bI d, there are integers s and t such that c = as and d = bt. Click and drag the given steps (in the right) to their corresponding step names (in the left) to show that if a l b and b a, where a and b are integers, then a = b or a =-b. Step 1 If a l b and bl a, there are integers c and d such that b ac and a bd. Because a 0, it follows that cd = 1. Step 2 If a l b and b I a, there are integers c and d such that b = a + c and a = b + d. Step 3 Thus either c = d = 1 or c = d =-1. Hence, a-a+c+d. Step 4 Hence, a = acd