[ Closed ] Help

You'll find your functions in pict. 1.
Please note that only real results are shown for the second function. Complex solution for any value x<0 can be found in Evaluate dialogue (Ctrl-E).

The equation  "y=√x - 5x" returns real solutions for x>=0, and complex solutions for x<0:
y= - 5x + i*sqrt(-x) ;
In picture 2 results in complex plane are shown, with x values advancing in 0.1 steps, just for better imagination.