Let x be the the cost of the woolen shirt. Since the woolen shirt cost $25 more than a cotton shirt, the price of the cotton shirt can be express as
[tex]x-25[/tex]We know that 3 cotton shirts and a woolen shirt cost $145, then:
[tex]3(x-25)+x=145[/tex]Solving for x, we have
[tex]\begin{gathered} 3(x-25)+x=145 \\ 3x-75+x=145 \\ 4x=145+75 \\ 4x=220 \\ x=\frac{220}{4} \\ x=55 \end{gathered}[/tex]Therefore, the woolen shirt cost $55.
