Đáp án:
e) `x=3/2` hoặc `x=-6`
f) `x=1` hoặc `x=7/2`
Giải thích các bước giải:
$e)\ |9-x|-x=3+2x\\\Rightarrow |9-x|=3+3x\\\Rightarrow \left[ \begin{array}{l}9-x=3+3x\\9-x=-3-3x\end{array} \right.\\\Rightarrow \left[ \begin{array}{l}4x=6\\2x=-12\end{array} \right.\\\Rightarrow \left[ \begin{array}{l}x=\dfrac{3}{2}\\x=-6\end{array} \right.$
Vậy `x=3/2` hoặc `x=-6`
$f)\ -6-3x+|x+8|=0\\\Rightarrow |x+8|=6+3x\\\Rightarrow \left[ \begin{array}{l}x+8=6+3x\\x+8=-6-3x\end{array} \right.\\\Rightarrow \left[ \begin{array}{l}2x=2\\4x=-14\end{array} \right.\\\Rightarrow \left[ \begin{array}{l}x=1\\x=\dfrac{7}{2}\end{array} \right.$
Vậy `x=1` hoặc `x=7/2`
