a: \(\Leftrightarrow5\sqrt{x+2}+6\sqrt{x+2}-8\sqrt{x+2}=15\)
=>3 căn x+2=15
=>x+2=25
=>x=23
b: =>|x-3|=3x+5
\(\Leftrightarrow\left\{{}\begin{matrix}x>=-\dfrac{5}{3}\\\left(3x+5-x+3\right)\left(3x+5+x-3\right)=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x>=-\dfrac{5}{3}\\\left(2x+8\right)\left(4x+2\right)=0\end{matrix}\right.\Leftrightarrow x=-\dfrac{1}{2}\)