I don’t understand what tex means but this is the best I can understand the problem I hope it helps! When dividing fractions it’s best to have two fractions so you put the 20 over a 1 it should like this (20/1). Then you multiply a fraction by flipping your division sign to a multiplication sign and flipping the top and bottom number of the (3/4). This is your new equation (20/1)x(4/3) then you multiple across so 20x4 is 80and 3x1 is 3 so your answer to 20/(3/4) is 80/3.