Kohl's sells casual shirts for $9 and polo shirts for $18.00. total sales were $1,080, and customers bought 4 times as many casual as polo shirts. how many casual shirts did kohl's sell?

Let x be the number of polo shirts customers bought
      4x be the number of casual shirts bought by customers

Based on the condition that the total sales amounted to $1,080, the equation becomes
     
                               9(4x) + 18(x) = 1,080

This equation gives a value for x equal to 20.

Therefore, Kohl's sold 80 casual shirts. 

                        

Understanding what? lol