Description: Sal solves a word problem by subtracting mixed numbers with unlike denominators. Created by Sal Khan. So the beefsteak tomato type had a height of 3 and 1/4 feet, Roma 2 and 7/8 feet, cherry 3 and 1/2 feet. And they ask us, what is the difference between the heights of the beefsteak, so that's that one right over there, and the Roma tomato plants? So we want to find the difference in these two heights.*Teacher Advisor is 100% free.