Đáp án:
Giải thích các bước giải:
1) |4+2x|=-4x đk:x≤0
⇔\(\left[ \begin{array}{l}4+2x=-4x\\4+2x=4x\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-\frac{2}{3}\\x=2\end{array} \right.\)
⇔x=-$\frac{2}{3}$
vậy:s={-$\frac{2}{3}$}
2) |9+x|= 2x đk:x≥0
⇔\(\left[ \begin{array}{l}9+x=2x\\9+x=-2x\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=9\\x=-3\end{array} \right.\)
⇔x=9
vậy:s={9}
3) |x-1|= |3-2x|
⇔\(\left[ \begin{array}{l}x-1=3-2x\\x-1=2x-3\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\frac{4}{3}\\x=2\end{array} \right.\)
vậy:s={2;$\frac{4}{3}$}
4) |0,5x|=3-2x đk:x≤1,5
⇔\(\left[ \begin{array}{l}0,5x=3-2x\\0,5x=2x-3\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=1,2\\x=2\end{array} \right.\)
⇔x=1,2
vậy:s={1,2}
5) |-2x|=4x+18 đk:x≥-4,5
⇔\(\left[ \begin{array}{l}2x=4x+18\\2x=-4x-18\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-9\\x=-3\end{array} \right.\)
⇔x=-3
vậy:s={-3}
