If x and y are right angles, then x and y are complementary (Never, sometimes, always) fill in the blank

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-2 and g(x) =2x+1 fins (f+ g) (x)

If the scale factor between two circles is 2x/5y what is the ratio of their areas?