Laplace transform is only for continuous systems? Explain

Create a real-life situation and create a system and show how it might be modeled algebraically with a system of equations (or inequalities) show all work include a few sentences explaining the situation, your variables of choice and what each represents, and how you would set it up and solve it algebraically. !

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

The circle below is centered at the point (3, 1) and has a radius of length 2. what is the equation?