Đáp án:
Giải thích các bước giải:
$\text{(3x+5)²=9}$
$\text{(3x+5)²-3²=0}$
$\text{⇒\(\left[ \begin{array}{l}3x+5=3\\3x+5=-3\end{array} \right.\) }$
$\text{⇒\(\left[ \begin{array}{l}3x=-2\\3x=-8\end{array} \right.\) }$
$\text{⇒\(\left[ \begin{array}{l}x=-\frac{2}{3}\\x=-\frac{8}{3} \end{array} \right.\)}$