Question 453794
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Solve by completing the square.
x^2+4x-12=0
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        In his post, @mananth found one root, but missed/lost another root.

        So, his solution is incomplete.

        I came to bring a complete solution.



<pre>
x^2 + 4x - 12 = 0

x^2 + 4x = 12

x^2 + 4x + 4 = 12 + 4

(x+2)^2 = 16

x + 2 = +/- {{{sqrt(16)}}}

x + 2 = +/- 4


Case (a).  x + 2 = 4  --->  x = 4 - 2 = 2.


Vase (b).  x + 2 = -4 --->  x = -4 - 2 = -6.


Thus, equation  x^2 + 4x - 12 = 0  has two roots:  x = 2  and  x = -6.


Substitute these values into the equation to make sure that they do satisfy this equation.
</pre>

Solved correctly and completely.