a) -21/13x + 1/3 = -2/3
<=> -21/13 +x/3=-2x/3;
<=> x=21/13;
.
b) |x - 1,5| = 2
<=> \(\left[ \begin{array}{l}x - 1,5 = 2\\x - 1,5 = -2\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x = 3,5\\x = -0,5\end{array} \right.\)
.
c) |x+3/4|-1/2=0
<=> |x+3/4|=1/2;
<=> \(\left[ \begin{array}{l}x+3/4=1/2\\x+3/4=-1/2\end{array} \right.\) ;
<=> \(\left[ \begin{array}{l}x=-1/4\\x-5/4\end{array} \right.\)
.
g) |x - 2| = x
<=> \(\left[ \begin{array}{l}x-2=x\\x-2=-x\end{array} \right.\)
<=> \(\left[ \begin{array}{l}0=2 (vô nghiệm)\\x=1\end{array} \right.\)
vậy x=1
.
