The final price of the shirt is given by the regular price minus the discount value. Since the final price is $28, the regular price is p, and the discount is $16, the equation is
[tex]p-16=28[/tex]If we add 16 to both sides of the equation, we have
[tex]\begin{gathered} p-16+16=28+16 \\ p=28+16 \end{gathered}[/tex]If we invert the order of the equality, we get the last option as the answer
[tex]16+28=p[/tex]