What is the solution of square root of x plus 12 end root is equal to x ?

The square root requires x to be nonnegative. Squaring both sides gives x + 12 = x², or (x − 4)(x + 3) = 0, so the candidates are x = 4 and x = −3. Since −3 is negative, it cannot satisfy the original equation; x = 4 does, so the solution is x = 4.

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