√(5-x) + 3 = x
Isolate the radical: √(5-x) = x-3
Square both sides: 5-x = x2 - 6x + 9
Solve for x: x2 - 5x + 4 = 0
(x-4)(x-1) = 0
x = 4 or 1
Note that 1 does not satisfy the original equation, so 1 must be excluded from the solution set.
So, the only solution is 4.