Giải phương trình sau : 9(2x + 3)^2 = (3x - 2)^2

* Hướng dẫn giải

$\begin{array}{l}9{\left(2x+3\right)}^2={\left(3x-2\right)}^2\\ \iff {\left[3\left(2x+3\right)\right]}^2-{\left(3x-2\right)}^2=0\\ \iff \left[3\left(2x+3\right)-3x+2\right]\left[3\left(2x+3\right)+3x-2\right]=0\\ \iff \left(3x+11\right)\left(9x+7\right)=0\\ \iff \left[\begin{array}{l}3x+11=0\\ 9x+7=0\end{array}\right.\iff \left[\begin{array}{l}x=-\frac{11}{3}\\ x=-\frac{7}{9}\end{array}\right.\end{array}$