Đáp án:

• Đặt \( t = \frac{2x - 1}{3x + 2} \Rightarrow dt = \frac{7}{(3x + 2)^2} \, dx \)

• \( \int \left[\frac{(2x - 1)}{(3x + 2)}\right]^3 \frac{1}{(3x + 2)^2} \, dx = \frac{1}{7} \int t^3 \, dt = \frac{t^4}{28} + C \)