How do you solve $sqrt(x+12)=x$ ?

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Answer 1 · 2015-05-19T07:54:16

$sqrt(x+12) =x$

squaring both the sides
$(sqrt(x+12))^2 =x^2$
$x+12 = x^2$
$x^2 -x -12 =0$

we can find the roots by Splitting the Middle Term of this expression to factorise it:

$x^2 -x -12 = x^2 -4x +3x -12$
$= x(x-4)+3 (x-4)$
$= (x+3)(x-4)$

the solution is $color(blue)x=-3 , color(blue)x=4$

How do you solve sqrt(x+12)=xsqrt(x+12)=x?