Answer:
x = 4 is the solution
Step-by-step explanation:
given = x ( square both sides )
x + 12 = x² ( rearrange into standard form )
x² - x - 12 = 0 ← in standard form
(x - 4 )(x + 3 ) = 0 ← in factored form
equate each factor to zero and solve for x
x - 4 = 0 ⇒ x = 4
x + 3 = 0 ⇒ x = - 3
Insert these values into the original equation, and if both sides are equal, and those are the solutions.
x = 4 : = = 4 = x ← correct
x = - 3 : = = 3 ≠ - 3 ← false
the answer is x = 4
