Question

Tính x biết:

a) |x-2/5|=1/4

b) |x+0, 5|-3, 9=0

Gíup mìk vs

Answer 1

Giải:

a) \(\left|x-\dfrac{2}{5}\right|=\dfrac{1}{4}\)

\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{2}{5}=\dfrac{1}{4}\\x-\dfrac{2}{5}=-\dfrac{1}{4}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{13}{20}\\x=\dfrac{3}{20}\end{matrix}\right.\)

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b) \(\left|x+0,5\right|-3,9=0\)

\(\Leftrightarrow\left|x+0,5\right|=3,9\)

\(\Leftrightarrow\left[{}\begin{matrix}x+0,5=3,9\\x+0,5=-3,9\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3,4\\x=-4,4\end{matrix}\right.\)

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Answer 2

a) ⇔x−25=14x−25=−14⇔x−25=14x−25=−14