a)
\(\left|x-1\right|=3x+2\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x-1=3x+2\\1-x=3x+2\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x=-\frac{2}{3}\\x=-\frac{1}{4}\end{array}\right.\)
b)
\(\left|4+2x\right|=-4x\)
\(\Rightarrow\left[\begin{array}{nghiempt}4+2x=-4x\\4+2x=4x\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=-\frac{2}{3}\\x=1\end{array}\right.\)
c)
\(\left|3x-1\right|+2=x\)
\(\Rightarrow\left[\begin{array}{nghiempt}3x-1+2=x\\3x-1+2=-x\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=-\frac{1}{2}\\x=-\frac{1}{4}\end{array}\right.\)
d)
\(\left|7-2x\right|+7=2x\)
\(\Rightarrow\left[\begin{array}{nghiempt}7-2x+7=2x\\7-2x+7=-2x\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{7}{2}\\14=0\end{array}\right.\)
=> x = 7 / 2
