Giải thích các bước giải:
`a)`
`|x|= 8`
`⇒ x = ± 8`
`b)`
`|x + 2|= 9`
`⇔` \(\left[ \begin{array}{l}x+ 2 = 9\\x + 2= -9\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=7\\x=-7\end{array} \right.\)
`c)`
`8 + |x - 1|= -15 + 28`
`⇔ 8 + |x - 1|= 13`
`⇔ | x- 1 | = 13- 8`
`⇔ | x - 1| = 5`
`⇔` \(\left[ \begin{array}{l}x- 1 = 5\\x-1 = -5\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=6\\x=-4\end{array} \right.\)
d)
`|x - 5|= 26 + ( -6 )`
`⇔|x - 5 | = 20`
`⇔` \(\left[ \begin{array}{l}x-5 = 20\\x - 5 = - 20\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=25\\x=-15\end{array} \right.\)
