Let x be the number of rolls purchased and y the total cost.
The equation that describes the total cost for freshmen is:
[tex]44+101x=y[/tex]The equation that describes the total cost for sophomores is:
[tex]55+100x=y[/tex]Make both equations for y equal and solve for x:
[tex]\begin{gathered} 44+101x=55+100x \\ 101x-100x=55-44 \\ x=11 \end{gathered}[/tex]Use the value of x to find y:
[tex]\begin{gathered} 55+100(11)=y \\ 55+1100=y \\ 1155=y \end{gathered}[/tex]It means that the two classes will have each spend $1155 in total by buying 11 rolls.