`a, x + 4 = -14 - 9`
`⇒ x + 4 = -23`
`⇒ x = -23 - 4`
`⇒ x = -27`
Vậy `x = -27`
`b, 3x = -14 + 2`
`⇒ 3x = -12`
`⇒ x = -12 : 3`
`⇒ x = -4`
Vậy `x = -4`
`c, 2 . |x| = 4 - (-8)`
`⇒ 2 . |x| = 4 + 8`
`⇒ 2 . |x| = 12`
`⇒ |x| = 12 : 2`
`⇒ |x| = 6`
`⇒` \(\left[ \begin{array}{l}x=6\\x=-6\end{array} \right.\)
Vậy `x ∈ { 6 ; -6 }`
`d, |x - 2| = 7`
`⇒` \(\left[ \begin{array}{l}x-2=7\\x-2=-7\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=7+2=9\\x=-7+2=-5\end{array} \right.\)
Vậy `x ∈ { 9 ; -5 }`
