The solution set sqrt3x+16=x+2 is (only 3x+16 is squared)

Sqrt (3x + 16) = x + 2

3x + 16 = (x + 2) ^2 = x^2 + 4x + 4

x^2 + 4x - 3x + 4 - 16 = 0

x^2 + x - 12 = 0

(x - 3) (x + 4) = 0

x - 3 = 0 or x + 4 = 0

x = 3 or x = - 4.

Solution set = {-4, 3}