a)$|2-x|+3=x$
$|2-x|=x-3$
⇒\(\left[ \begin{array}{l}2-x=x-3\\2-x=3-x\end{array} \right.\)
⇒\(\left[ \begin{array}{l}2+3=x+x\\2-3=x-x\end{array} \right.\)
⇒\(\left[ \begin{array}{l}2x=5\\-1=0x (vô lý)\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=\frac{5}{2}\\x ko có giá trị\end{array} \right.\)
Vậy $x=\frac{5}{2}$
b) $2|x+1|-x=3x$
$2.|x+1|=4x$
$|x+1|=2x$
⇒\(\left[ \begin{array}{l}x+1=2x\\x+1=-2x\end{array} \right.\)
⇒\(\left[ \begin{array}{l}1=2x-x\\1=-2x-x\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=1\\1=-3x\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=1\\x=-\frac{1}{3}\end{array} \right.\)
Vậy $x=1$ hoặc $x=-\frac{1}{3}$
c)$|4x-2|-3x=4$
$|4x-2|=4+3x$
⇒\(\left[ \begin{array}{l}4x-2=4+3x\\4x-2=-4-3x\end{array} \right.\)
⇒\(\left[ \begin{array}{l}4x-3x=4+2\\4x+3x=-4+2\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=6\\7x=-2\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=6\\x=-\frac{2}{7}\end{array} \right.\)
Vậy $x=6,x=-\frac{2}{7}$
