\(\sqrt{18x+9}-\sqrt{8x+4}+\dfrac{1}{3}\sqrt{2x+1}=4\) (đk:\(x\ge-\dfrac{1}{2}\))
\(\Leftrightarrow\sqrt{9\left(2x+1\right)}-\sqrt{4\left(2x+1\right)}+\dfrac{1}{3}\sqrt{2x+1}=4\)
\(\Leftrightarrow3\sqrt{2x+1}-2\sqrt{2x+1}+\dfrac{1}{3}\sqrt{2x+1}=4\)
\(\Leftrightarrow\sqrt{2x+1}=3\)
\(\Leftrightarrow x=4\)(TM)
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