+) |x-5|=|-7|;
<=> |x-5|=7;
<=> \(\left[ \begin{array}{l}x-5=7\\x-5=-7\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=12\\x=-2\end{array} \right.\)
.
+) |x-3|=7-(-2);
<=> |x-3|=7+2=9
<=>\(\left[ \begin{array}{l}x-3=9\\x-3=-9\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=12\\x=-6\end{array} \right.\)
.
+) <=> |x-3|=5+7=12;
<-> \(\left[ \begin{array}{l}x-3=12\\x-3=-12\end{array} \right.\) ;
<=> \(\left[ \begin{array}{l}x=15\\x=-9\end{array} \right.\) ;