a)|5x-3|<2
\(\Leftrightarrow\left\{{}\begin{matrix}5x-3>-2\\5x-3< 2\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}5x>1\\5x< 5\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x>\frac{1}{5}\\x< 1\end{matrix}\right.\) x thuộc Z => vô nghiệm
b)|3x+1|>4
\(\Leftrightarrow\left\{{}\begin{matrix}3x+1>4\\3x+1< -4\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}3x>3\\3x< -5\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x>1\\x< -\frac{5.}{3}\end{matrix}\right.\)x∈Z∖{−1;0;1}
c)|4-x|+2x=3
\(\Leftrightarrow\left|x-4\right|=3-2x\)
\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x\ge4\\x-4=3-2x\Rightarrow x=\frac{7}{3}\left(l\right)\end{matrix}\right.\\\left\{{}\begin{matrix}x< 4\\x-4=2x-3\Rightarrow x=-1\left(n\right)\end{matrix}\right.\end{matrix}\right.\)
