giải phương trình (3x+1).(3x-2) / 3 +5.(3x+1)=2.(2x+1).(3x+1) / 3+ 2x.(3x+1)

Đáp án:

$\begin{array}{l}
\frac{{\left( {3x + 1} \right)\left( {3x – 2} \right)}}{3} + 5\left( {3x + 1} \right) = \frac{{2\left( {2x + 1} \right)\left( {3x + 1} \right)}}{3} + 2x\left( {3x + 1} \right)\\
 \Rightarrow \left( {3x + 1} \right).\left( {\frac{{3x – 2}}{3} + 5 – \frac{{2\left( {2x + 1} \right)}}{3} – 2x} \right) = 0\\
 \Rightarrow \left[ \begin{array}{l}
3x + 1 = 0\\
\frac{{3x – 2 + 15 – 4x – 2 – 6x}}{3} = 0
\end{array} \right.\\
 \Rightarrow \left[ \begin{array}{l}
x =  – \frac{1}{3}\\
 – 7x + 11 = 0
\end{array} \right.\\
 \Rightarrow \left[ \begin{array}{l}
x = \frac{1}{3}\\
x = \frac{{11}}{7}
\end{array} \right.
\end{array}$