a: Ta có: \(\sqrt{3x+1}=4\)
\(\Leftrightarrow3x+1=16\)
\(\Leftrightarrow3x=15\)
hay x=5
b: Ta có: \(\sqrt{x^2-10x+25}=12\)
\(\Leftrightarrow\left|x-5\right|=12\)
\(\Leftrightarrow\left[{}\begin{matrix}x-5=12\\x-5=-12\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=17\\x=-7\end{matrix}\right.\)
c: Ta có: \(3\sqrt{4x+8}-\sqrt{25x+50}+\sqrt{x+2}=2\)
\(\Leftrightarrow6\sqrt{x+2}-5\sqrt{x+2}+\sqrt{x+2}=2\)
\(\Leftrightarrow2\sqrt{x+2}=2\)
\(\Leftrightarrow x+2=1\)
hay x=-1