Giải thích các bước giải:
`d) |x| - (-5) = 11 + (-1)`
`=>|x|+5=11-1`
`=>|x|+5=10`
`=>|x|=10-5`
`=>|x|=5`
`=>`\(\left[ \begin{array}{l}x=5\\x=-5\end{array} \right.\)
`f) |x-5| - |-7| = -3`
`=>|x-5|-7=-3`
`=>|x-5|=-3+7`
`=>|x-5|=4`
`=>`\(\left[ \begin{array}{l}x-5=4\\x-5=-4\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=4+5\\x=-4+5\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=9\\x=1\end{array} \right.\)
`g) 3.|x| - 12 = 16 - 4`
`=>3.|x|-12=12`
`=>3.|x|=12+12`
`=>3.|x|=24`
`=>|x|=24:3`
`=>|x|=8`
`=>`\(\left[ \begin{array}{l}x=8\\x=-8\end{array} \right.\)
`i) |-x + 8| = -13 - (-21)`
`=>|-x+8|=-13+21`
`=>|-x+8|=8`
`=>`\(\left[ \begin{array}{l}-x+8=8\\-x+8=-8\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}-x=8-8\\-x=-8-8\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}-x=0(KTM)\\-x=-16\end{array} \right.\)
`=>x=16`
