[tex]x + y + z = 2017 \\ x + y = z \\ x - y = 254 \\ z + z = 2017 \\ 2z = 2017 \\ z = \frac{2017}{2} \\ x = 254 + y \\ 254 + y + y = \frac{2017}{2} \\ 254 + 2y = \frac{2017}{2} \\ 508 + 4y = 2017 \\ 4y = 2017 - 508 = 1509 \\ y = \frac{1509}{4} \\ x = 254 + \frac{1509}{2} = \frac{502 + 1509}{2} = \frac{2011}{2} [/tex]