Khi \(x< -5\) thì\(|x+5|=-x-5\)
\(\Leftrightarrow-x-5=2x-18\)
\(\Leftrightarrow-3x=-13\)
\(\Leftrightarrow x=\frac{13}{3}\)(KTMĐK)
Khi \(x\ge-5\)thì \(|x+5|=x+5\)
\(\Leftrightarrow x+5=2x-18\)
\(\Leftrightarrow-x=-23\)
\(\Leftrightarrow x=23\)(TMĐK)
Vậy:\(S=\left\{23\right\}\)
\(\left|x+5\right|=2x-18\)
Ta có: \(x+5\ge0\Leftrightarrow x\ge-5\)
Trường hợp 1:
\(x+5=2x-18\)
\(\Leftrightarrow-x=-23\Leftrightarrow x=23\left(TMĐK\right)\)
Ta có: \(x+5< 0\Leftrightarrow x< -5\)
Trường hợp 2:
\(x+5=18-2x\)
\(\Leftrightarrow x+2x=18-5\Leftrightarrow3x=15\)
\(\Leftrightarrow x=5\left(KTMĐK\right)\)
Vậy bạn tự kết luận nha
