Bài 5. Tìm x, biết: a) \(1,5x - 2 \cdot \frac{1}{3}x = 1,5 - \frac{2}{3}\) b) \(5 \cdot \frac{6}{11}x + 8 \cdot \frac{9}{11}x + 2 \cdot \frac{3}{11} = 3 \cdot \frac{4}{11}x - \frac{8}{11}\) c) \(\frac{1}{3}x - \frac{2}{5}(x + 1) = 0\) d) \(\frac{1}{2}(x + 2) = -4\left(\frac{1}{2}x - \frac{3}{4}\right)\) e) \(\frac{x + 3}{-4} = \frac{5 - x}{5}\) f) \(1 + 2x = \frac{-3}{4} \left(x \neq \frac{3}{7}\right)\)