What is the best way to describe the solution of this system of equations?

y=-1/3x+4
3y-x=12

a. there are no solutions to the system.
b. there is one solution, (-12, 0)
c. there are infinitely many solutions.
d. there is one solution, (0,4).

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.

How to find the exponential function y=ca^x, with points (1,2) and (2,1)

What is the radical expression that is equivalent to the expression 27 1 over 5?