b: ĐKXĐ: x>=-2
\(\sqrt{16x+32}+\dfrac{2}{3}\cdot\sqrt{9x+18}-5\sqrt{\dfrac{x+2}{25}}=10\)
=>\(4\sqrt{x+2}+\dfrac{2}{3}\cdot3\sqrt{x+2}-5\cdot\dfrac{\sqrt{x+2}}{5}=10\)
=>\(5\sqrt{x+2}=10\)
=>\(\sqrt{x+2}=2\)
=>x+2=4
=>x=2(nhận)
\(b)\sqrt{16x+32}+\dfrac{2}{3}\sqrt{9x+18}-5\sqrt{\dfrac{x+2}{25}}=10\\ \Leftrightarrow\sqrt{16\left(x+2\right)}+\dfrac{2}{3}\sqrt{9\left(x+2\right)}-\sqrt{25\cdot\dfrac{x+2}{25}}=10\\ \Leftrightarrow4\sqrt{x+2}+2\sqrt{x+2}-\sqrt{\dfrac{25\left(x+2\right)}{25}}=10\\ \Leftrightarrow6\sqrt{x+2}-\sqrt{x+2}=10\\ \Leftrightarrow5\sqrt{x+2}=10\\ \Leftrightarrow\sqrt{x+2}=10:5\\ \Leftrightarrow\sqrt{x+2}=2\\ \Leftrightarrow\left(\sqrt{x+2}\right)^2=2^2\\ \Leftrightarrow x+2=4\\ \Leftrightarrow x=4-2\\ \Leftrightarrow x=2.\)
