ĐKXĐ: x>=-2
\(\sqrt{4x+8}+2\sqrt{9x+18}=7-\sqrt{x+2}\)
=>\(2\cdot\sqrt{x+2}+2\cdot3\sqrt{x+2}=7-\sqrt{x+2}\)
=>\(8\sqrt{x+2}+\sqrt{x+2}=7\)
=>\(9\sqrt{x+2}=7\)
=>\(\sqrt{x+2}=\dfrac{7}{9}\)
=>\(x+2=\left(\dfrac{7}{9}\right)^2=\dfrac{49}{81}\)
=>\(x=\dfrac{49}{81}-1=-\dfrac{113}{81}\)