The functions that are NOT linear from the given options are:
- \( y = x(3 - x) \) (This is a quadratic function)
The remaining functions are linear:
- \( y = 5(2x - 1) \)
- \( y = -2x + 4 \)
- \( y = \frac{1}{3}x - 5 \)
- \( y = 5 \)
So, the only function that is NOT linear is option 2.