Đáp án:
Giải thích các bước giải:
$3^{x-14}=3^2$
$⇒x-14=2$
$⇒x=16$
$b)(2x-1)^3=(2x-1)^2$
$⇒(2x-1)^3-(2x-1)^2=0$
$⇒(2x-1)^2.[ 2x-1-1]=0$
$⇒(2x-1)^2.(2x-2)=0$
$⇒$\(\left[ \begin{array}{l}2x-1=0\\2x-2=0\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}2x=1\\2x=2\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x=\dfrac{1}{2}\\x=1\end{array} \right.\)
$c)(x^2-4).(x^2-16)=0$
$⇒$\(\left[ \begin{array}{l}x^2-4=0\\x^2-16=0\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x^2=4\\x^2=16\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x=±2\\x=±4\end{array} \right.\)
