a) \(\frac{3}{2}+\frac{7}{4}x=-\frac{5}{8}\)
\(\Rightarrow\frac{7}{4}x=\left(-\frac{5}{8}\right)-\frac{3}{2}\)
\(\Rightarrow\frac{7}{4}x=-\frac{17}{8}\)
\(\Rightarrow x=\left(-\frac{17}{8}\right):\frac{7}{4}\)
\(\Rightarrow x=-\frac{17}{14}\)
Vậy \(x=-\frac{17}{14}.\)
b) \(\left|x-\frac{3}{7}\right|=\frac{1}{4}\)
\(\Rightarrow\left[{}\begin{matrix}x-\frac{3}{7}=\frac{1}{4}\\x-\frac{3}{7}=-\frac{1}{4}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{1}{4}+\frac{3}{7}\\x=\left(-\frac{1}{4}\right)+\frac{3}{7}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{19}{28}\\x=\frac{5}{28}\end{matrix}\right.\)
Vậy \(x\in\left\{\frac{19}{28};\frac{5}{28}\right\}.\)
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