giải pt

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vipboycodon

$2\sqrt{x+4}-4\sqrt{2x-6} = x-7$
<=> $2(\sqrt{x+4}-3)-4(\sqrt{2x-6}-2)-(x-5) = 0$
<=> $\dfrac{2(x-5)}{\sqrt{x+4}+3}-\dfrac{4(2x-10)}{\sqrt{2x-6}+2}-(x-5) = 0$
<=> $(x-5)(\dfrac{2}{\sqrt{x+4}+3}-\dfrac{8}{\sqrt{2x-6}+2}-1) = 0$
<=> $x = 5$
 
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