The cost of each shoe is $110
Here, we want to get the cost of the new shirts before discount
Let the cost of each of the shirts be c
5 of these shirts will have a cost of;
[tex]5\times c\text{ = 5c}[/tex]The discount on each of the shirt was $10;
So, the total discount amount will be;
[tex]5\times10\text{ = \$50}[/tex]The sum of both equals the total before tax
Mathematically, we have this as;
[tex]\begin{gathered} 5c\text{ + 50 = 600} \\ 5c\text{ = 600-50} \\ 5c\text{ = 550} \\ c\text{ = }\frac{550}{5} \\ c\text{ = \$110} \end{gathered}[/tex]