The difference of two numbers is equal to 0.6. their quotient is also 0.6. what are the numbers? there are 4

Let the two numbers be represented by x and y. The problem statement gives rise to two sets of equations.
  x - y = 0.6
  y/x = 0.6 . . . . . . . assuming x is the larger of the two numbers
or
  x/y = 0.6 . . . . . . . assuming y has the larger magnitude

The solution of the first pair of equations is
  (x, y) = (1.5, 0.9)

The solution of the first and last equations is
  (x, y) = (-0.9, -1.5)

The pairs of numbers could be {0.9, 1.5} or {-1.5, -0.9}.