Subtract -7x^2+4x+2−7x 2 +4x+2 from x^2-3x 2 −3

The difference of 2 numbers is 21 and the quotient of the equation is 4 then what are the two numbers?

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.

Need solving this 2nd limit problem.