Question

Выполните умножение:
$- \frac{1}{9}(0.5 {a}^{2} {b}^{2} - ab + 0.9)( - ab) = ... \\ - {b}^{3} ( - 0.3 {a}^{2} b \: - 0.4ab + 1) \times \frac{1}{6} {a}^{2} {b}^{2} = ...$

Answer 1

1)
$- \frac{1}{9} ( \frac{5}{10} a {}^{2} b {}^{2} - ab + \frac{9}{10} )( - ab) = \\ \\ =( - \frac{1}{18} a {}^{2} b {}^{2} + \frac{1}{9} ab - 0.1)( - ab) = \\ \\ = \frac{1}{18} a {}^{3} b {}^{3} - \frac{1}{9} a {}^{2} b {}^{2} + 0.1ab$

2)
$- b {}^{3} ( - 0.3a {}^{2} b - 0.4ab + 1) \times \frac{1}{6} a {}^{2} b {}^{2} = \\ \\ = ( \frac{3}{10} a {}^{2} b {}^{4} + \frac{4}{10} ab {}^{4} - b {}^{3} ) \times \frac{1}{6} a {}^{2} b {}^{2} = \\ \\ = 0.05a {}^{4} b {}^{6} + \frac{1}{15} a {}^{3} b {}^{6} - \frac{1}{6} a {}^{2} b {}^{5}$