Answer :
[tex]\huge\text{Hey there!}[/tex]
[tex]\large\text{If we were to find the difference between the two years you have}\\\large\text{provided you would have to go back (almost like you're going}\\\large\text{back in time). You're going to take the highest year (238 B.C.)}\\\large\text{from the lowest year (15 B.C.) and you should have your equation}\\\large\text{and answer if you did what you were told.}[/tex]
[tex]\large\text{Equation: }\rm{238\ B.C. - 15\ B.C.}[/tex]
[tex]\large\text{Get your number line ready because this will make the equation easier to}\\\large\text{solve.}[/tex]
[tex]\large\text{Start at 238 and go back 15 spaces to your 15 to your left.}[/tex]
[tex]\large\text{If you did the right calculation you should be at: 223}[/tex]
[tex]\huge\text{Thus, your answer can be: \boxed{\mathsf{238\ B.C. - 15\ B.C. }}}\huge\checkmark[/tex]
[tex]\large\text{Remember: \textsf{difference} means subtraction/subtract}[/tex]
[tex]\huge\text{Good luck on your assignment \& enjoy your day!}[/tex]