14-| 3x/2-1| =9 |4x|-|-13,5|=|9/4| 11/12-2/3|x|=3/8 04/12/2021 Bởi Liliana 14-| 3x/2-1| =9 |4x|-|-13,5|=|9/4| 11/12-2/3|x|=3/8
Giải thích các bước giải: $a)14-|\dfrac{3x}{2}-1|=9$ $⇔|\dfrac{3x}{2}-1|=5$ $⇔\dfrac{3x}{2}-1=±5$ $\left[ \begin{array}{l}\dfrac{3x}{2}-1=5\\\dfrac{3x}{2}-1=-5\end{array} \right.⇔\left[ \begin{array}{l}\dfrac{3x}{2}=6\\\dfrac{3x}{2}=-4\end{array} \right.⇔\left[ \begin{array}{l}3x=12\\3x=-8\end{array} \right.⇔\left[ \begin{array}{l}x=4\\x=-\dfrac{8}{3}\end{array} \right.$ $\text{Vậy $x∈\{-\dfrac{8}{3};4\}$}$ $b)|4x|-|-13,5|=\dfrac{9}{4}$ $⇔|4x|-13,5=\dfrac{9}{4}$ $⇔|4x|=\dfrac{63}{4}$ $\left[ \begin{array}{l}4x=\dfrac{63}{4}\\4x=-\dfrac{63}{4}\end{array} \right.⇔\left[ \begin{array}{l}x=\dfrac{63}{16}\\x=-\dfrac{63}{16}\end{array} \right.$ $\text{Vậy $x=±\dfrac{63}{16}$}$ $c)\dfrac{11}{12}-\dfrac{2}{3}|x|=\dfrac{3}{8}$ $⇔\dfrac{2}{3}|x|=\dfrac{13}{24}$ $⇔|x|=\dfrac{13}{24}:\dfrac{2}{3}$ $⇔|x|=\dfrac{13}{16}$ $⇔x=±\dfrac{13}{16}$ $\text{Vậy $x=±\dfrac{13}{16}$}$ Học tốt!!! Bình luận
Giải thích các bước giải:
$a)14-|\dfrac{3x}{2}-1|=9$
$⇔|\dfrac{3x}{2}-1|=5$
$⇔\dfrac{3x}{2}-1=±5$
$\left[ \begin{array}{l}\dfrac{3x}{2}-1=5\\\dfrac{3x}{2}-1=-5\end{array} \right.⇔\left[ \begin{array}{l}\dfrac{3x}{2}=6\\\dfrac{3x}{2}=-4\end{array} \right.⇔\left[ \begin{array}{l}3x=12\\3x=-8\end{array} \right.⇔\left[ \begin{array}{l}x=4\\x=-\dfrac{8}{3}\end{array} \right.$
$\text{Vậy $x∈\{-\dfrac{8}{3};4\}$}$
$b)|4x|-|-13,5|=\dfrac{9}{4}$
$⇔|4x|-13,5=\dfrac{9}{4}$
$⇔|4x|=\dfrac{63}{4}$
$\left[ \begin{array}{l}4x=\dfrac{63}{4}\\4x=-\dfrac{63}{4}\end{array} \right.⇔\left[ \begin{array}{l}x=\dfrac{63}{16}\\x=-\dfrac{63}{16}\end{array} \right.$
$\text{Vậy $x=±\dfrac{63}{16}$}$
$c)\dfrac{11}{12}-\dfrac{2}{3}|x|=\dfrac{3}{8}$
$⇔\dfrac{2}{3}|x|=\dfrac{13}{24}$
$⇔|x|=\dfrac{13}{24}:\dfrac{2}{3}$
$⇔|x|=\dfrac{13}{16}$
$⇔x=±\dfrac{13}{16}$
$\text{Vậy $x=±\dfrac{13}{16}$}$
Học tốt!!!