First, we need to find what 12*2 is. 12*2=24 Next,we need to find out what 9*2 is. 9*2=18 24=18=42. Finally, we need to find out which of the following equals 42. 21*2=42, 21*4=84, 22*2=44, and 22*4=88 21*2=42,so that is your answer. Hope this helped
