a) |x-5| = 7 ⇒ x-5 = ±7 ⇒ \(\left[ \begin{array}{l}x-5=7\\x-5=-7\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=7+5\\x=-7+5\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=12\\x=-2\end{array} \right.\)
Vậy x=12 hoặc x=-7
b) 59 - (x+7) = 60 ⇒ x+7 = 59 - 60
⇒ x+7 = -1
⇒ x = -1 - 7
Vậy x = -8
c) (x-2). (x+7) = 0 ⇒ \(\left[ \begin{array}{l}x-2=0\\x+7=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=2\\x=-7\end{array} \right.\)
Vậy x=2 hoặc x=-7
