a)x-14=3x+18
⇔x-3x=18+14
⇔-2x=32
⇔ x=-16
Vậy x=-16
b)2(x-5)-3(x-4)=-6+15(-3)
⇔2x-10-3x+12=-6-45
⇔2x-3x=-6-45+10-12
⇔-x=-53
⇔x=53
Vậy x=53
c)(x+7)(x-9)=0
⇔\(\left[ \begin{array}{l}x+7=0\\x-9=0\end{array} \right.\)⇔\(\left[ \begin{array}{l}x=0-7\\x=0+9\end{array} \right.\)⇔\(\left[ \begin{array}{l}x=-7\\x=9\end{array} \right.\)
Vậy x=-7; x=9
d)|2x-5|=22+7
⇔|2x-5|=29
⇔\(\left[ \begin{array}{l}2x-5=29\\2x-5=-29\end{array} \right.\)⇔\(\left[ \begin{array}{l}2x=29+5\\2x=-29+5\end{array} \right.\)⇔\(\left[ \begin{array}{l}2x=34\\2x=-24\end{array} \right.\)⇔\(\left[ \begin{array}{l}x=34:2\\x=-24:2\end{array} \right.\)⇔\(\left[ \begin{array}{l}x=17\\x=-12\end{array} \right.\)
Vậy x=17; x=12.
