How do I solve this equation and check all the solutions?

Answer:
x = 12
Step-by-step explanation:
[tex]\sqrt{3x}[/tex] + 10 = x + 4
[tex]\sqrt{3x}[/tex] = x - 6
( [tex]\sqrt{3x}[/tex] )² = ( x - 6 )²
3x = x² - 12x + 36
x² - 15x + 36 = 0
(x - 3)(x - 12) = 0
[tex]x_{1}[/tex] = 3
[tex]x_{2}[/tex] = 12
Check the answer:
[tex]\sqrt{3*3}[/tex] + 10 ≠ 3 + 4
13 ≠ 7 ⇒ 3 is not the root of original equation (strange root)
[tex]\sqrt{3*12}[/tex] + 10 = 12 + 4
16 = 16 ⇒ 12 is the root of original equation