The sum of three numbers is 9 9. two times the smallest is 3 3 less than the largest, while the sum of the largest and smallest is 6 6. use a linear system in three variables to find the three numbers.

Let the three numbers be represented by x, y, and z, in order of size.
  x + y + z = 9
  -2x + 0y + z = 3
  x + 0y + z = 6

_____
A calculator finds the solution to these equations to be
  (x, y, z) = (1, 3, 5)

The three numbers are 1, 3, 5.

The answer maybbe c