1 câu trả lời
\(3\sqrt{25x+25} +\dfrac{3}{4}\sqrt{4x+4} -\sqrt{100x+100 }=16\)
ĐK: \(x\ge-1\)
PT \(\Leftrightarrow 3\sqrt{25(x+1)}+\dfrac{3}{4}\sqrt{4(x+1)}-\sqrt{100(x+1)}=16\)
\(\Leftrightarrow 3.\sqrt{25}\sqrt{x+1}+\dfrac{3}{4}\sqrt{4}\sqrt{x+1}-\sqrt{100}\sqrt{x+1}=16\)
\(\Leftrightarrow 15\sqrt{x+1}+\dfrac{3}{2}\sqrt{x+1}-10\sqrt{x+1}=16\)
\(\Leftrightarrow \sqrt{x+1}(15+\dfrac{3}{2}-10)=16\)
\(\Leftrightarrow \sqrt{x+1}=\dfrac{19}{2}\) (tm).
\(\Leftrightarrow x+1=\left({\dfrac{19}{2}}\right)^2\)
\(\Leftrightarrow x=\dfrac{357}{4}\)