1) [tex] - \frac{1}{9}(0.5 {a}^{2} {b}^{2} - ab + 0.9)( - ab) = \frac{1}{9}(0.5 {a}^{2} {b}^{3} + ab^2 - 0.9ab) = \frac{0.5 {a}^{2} {b}^{3}}{9} + \frac{ab^2}{9} - \frac{0.9ab}{9} = \frac{1}{18} {a}^{2} {b}^{3} + \frac{ab^2}{9} - \frac{ab}{10}[/tex]
2) [tex]- b^{3} ( - 0.3 {a}^{2} b - 0.4ab + 1) \times \frac{1}{6} {a}^{2} {b}^{2} = \frac{1}{6} b^{3} (0.3 {a}^{2} b + 0.4ab - 1) = \frac{0.3b^{3} {a}^{2} b}{6} + \frac{0.4b^{4} a}{6} - \frac{b^{3}}{6} = \frac{0.05b^{4} {a}^{2} + 0.067b^{4} a - b^{3}}{2}[/tex]
1) [tex] - \frac{1}{9}(0.5 {a}^{2} {b}^{2} - ab + 0.9)( - ab) = \frac{1}{9}(0.5 {a}^{2} {b}^{3} + ab^2 - 0.9ab) = \frac{0.5 {a}^{2} {b}^{3}}{9} + \frac{ab^2}{9} - \frac{0.9ab}{9} = \frac{1}{18} {a}^{2} {b}^{3} + \frac{ab^2}{9} - \frac{ab}{10}[/tex]
2) [tex]- b^{3} ( - 0.3 {a}^{2} b - 0.4ab + 1) \times \frac{1}{6} {a}^{2} {b}^{2} = \frac{1}{6} b^{3} (0.3 {a}^{2} b + 0.4ab - 1) = \frac{0.3b^{3} {a}^{2} b}{6} + \frac{0.4b^{4} a}{6} - \frac{b^{3}}{6} = \frac{0.05b^{4} {a}^{2} + 0.067b^{4} a - b^{3}}{2}[/tex]