Tìm số nguyên x , biết: a) x – 25 = -17 b) 2x – (-3) = 7 c) / x + 4 = 5 d) / x -8/ = 0

a) $x – 25 = -17$
⇔ $x = -17 + 25$ 
⇔ $x = 8$

b) $2x – ( -3 ) = 7$
⇔ $2x + 3 = 7$
⇔ $2x = 7 – 3$
⇔ $2x = 4$
⇔ $x = 4 ÷ 2$
⇔ $x = 2$

c) $| x + 4 | = 5$
⇔ \(\left[ \begin{array}{l}x+4=5\\x+4=-5\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}x=1\\x=-9\end{array} \right.\)

d) $| x – 8 | = 0$

⇔ $x – 8 = 0$
⇔ $x = 8$