a: Ta có: \(\sqrt{x-3}+\sqrt{4x-12}-\dfrac{1}{3}\sqrt{9x-27}=3\)
\(\Leftrightarrow\sqrt{x-3}+2\sqrt{x-3}-\dfrac{1}{3}\cdot3\sqrt{x-3}=3\)
\(\Leftrightarrow2\sqrt{x-3}=3\)
\(\Leftrightarrow x-3=\dfrac{9}{4}\)
hay \(x=\dfrac{21}{4}\)
b: Ta có: \(\sqrt{4x-8}+\dfrac{1}{5}\sqrt{25x-50}-\sqrt{x-2}=4\)
\(\Leftrightarrow2\sqrt{x-2}+\dfrac{1}{5}\cdot5\sqrt{x-2}-\sqrt{x-2}=4\)
\(\Leftrightarrow\sqrt{x-2}=2\)
\(\Leftrightarrow x-2=4\)
hay x=6
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