$|x-\dfrac{2}{5}|+\dfrac{3}{4}=\dfrac{11}{4}$
$|x-\dfrac{2}{5}|=2$
$⇔x-\dfrac{2}{5}=±2$
$+,x-\dfrac{2}{5}=2$
$x=\dfrac{12}{5}$
$+,x-\dfrac{2}{5}=-2$
$x=\dfrac{-8}{5}$
Vậy `x∈{\frac{12}{5};\frac{-8}{5}}`
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$-1+|x+4,5|=-6,2$
$|x+4,5|=-5,2$ (vô lý)
$⇒$ Vô nghiệm
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$|x-\dfrac{1}{5}|=\dfrac{-1}{2}$ (vô lý)
$⇒$ Vô nghiệm
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$\dfrac{1}{3}-|x-\dfrac{1}{5}|=\dfrac{1}{2}$
$|x-\dfrac{1}{5}|=\dfrac{-1}{6}$ (vô lý)
$⇒$ Vô nghiệm
