In equation form that would be X20+10. He has X amount of 20 dollar bills, then a 10 dollar bill. We have to multiply X by 20 first, then add that to 10.
Hey! If Donald has one ten dollar bill then we know he has 10, now depending on what x is, that's how many 20 dollar bills he has, so without any further information we know that Donald has 10 + 20x dollars. Hope this helps!
