help plz

Solve for x:
sqrt(x) + 2 = sqrt(x + 100)

Raise both sides to the power of 2:
(sqrt(x) + 2)^2 = x + 100

Subtract x + 100 from both sides:
-100 + (sqrt(x) + 2)^2 - x = 0

-100 + (sqrt(x) + 2)^2 - x = 4 sqrt(x) - 96:
4 sqrt(x) - 96 = 0

Add 96 to both sides:
4 sqrt(x) = 96

Divide both sides by 4:
sqrt(x) = 24

Raise both sides to the power of two:
 
 x = 576

I could find only one positive value for x:

x = 576

I graphed the equations and found that the only value is x = 576