√x -2√x+5=8

Answer 1

-1√x + 5 = 8

-1√x = 3

√x = -3

x = 9

Answer 2

let z = √x
z - 2 z + 5 = 8
- z = 3
z = -3 = √x
so x = -3*-3 = 9
or did you mean
x - 2 √x + 5 = 8
in that case
z^2 - 2 z - 3 = 0
(z-3)(z+1) = 0
z = 3 or z = -1
if √x = 3, then x = 9
if √x = -1then x = 1

Answer 3

the problem is, √x is positive