Answer:
[tex] \frac{2 {a}^{2} }{3 {b}^{3} } \div \frac{6 {a}^{3} }{5 {b}^{2} } = \frac{2 {a}^{2} }{3 {b}^{3} } \times \frac{5 {b}^{2} }{6 {a}^{3} } = \frac{5}{9ab} \\ \\ \frac{ {x}^{2} - 5x + 6}{ {x}^{2} - 6x + 9} + \frac{4x - 12}{{x}^{2} - 6x + 9} \\ = \frac{{x}^{2} - 5x + 6 + 4x - 12}{{x}^{2} - 6x + 9} \\ = \frac{{x}^{2} - x - 6}{{x}^{2} - 6x + 9} \\ = \frac{(x - 3)(x + 2)}{(x - 3)(x - 3)} \\ = \frac{(x + 2)}{(x - 3)} \\ \\ \frac{3a}{a - b} - \frac{a + 2b}{a - b} \\ = \frac{3a - a + 2b}{a - b} \\ = \frac{2a - 2b}{a - b} \\ = 2\frac{a - b}{a - b} \\ = 2[/tex]
