Đáp án:
$a) x=∅$
$b) ⇒$\(\left[ \begin{array}{l}x=5\\x=6\end{array} \right.\)
$c) ⇒$\(\left[ \begin{array}{l}x=0\\x=1\end{array} \right.\)
Giải thích các bước giải:
$a) 3^{2x}+2=9^x+3$
$⇒9^x+2=9^x+3$
$⇒9^x+2-9^x+3=0$
$⇒5=0$ (Vô lí)
$⇒x=∅$
$b) (x-5)^4=(x-5)^6$
$⇒(x-5)^6=(x-5)^4$
$⇒(x-5)^6-(x-5)^4=0$
$⇒(x-5)^4×[(x-5)^2-1]=0$
$⇒$\(\left[ \begin{array}{l}(x-5)^4=0\\(x-5)^2-1=0\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x-5=0\\(x-5)^2=1\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x=5\\x-5=1\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x=5\\x=6\end{array} \right.\)
$c) x^{15}=x^2$
$⇒x^{15}-x^2=0$
$⇒x^2×(x^{13}-1)=0$
$⇒$\(\left[ \begin{array}{l}x^2=0\\x^{13}-1=0\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x=0\\x^{13}=1\end{array} \right.\)
$⇒$\(\left[ \begin{array}{l}x=0\\x=1\end{array} \right.\)
$\text{Xin hay nhất}$ 💖
