X=4/5 y=4/x+sqrt x +0.2 -5x what is the value of y

You seem to be saying that Y=4/X+SQRT X +0.2 -5X, and that x is given as 4/5.  To evaluate Y=4/X+SQRT X +0.2 -5X, replace each occurrence of x with 4/5:

y = 4 / (4/5) + sqrt(4/5) + 0.2 - 5(4/5)
   = 5            + 2 / sqrt(5)  + 0.2 - 4
Can you simplify this further?

$75 x .20=$15

75-15=$60