Question

а) 0,8 * (-0,3) - 0,6 * (-0,3); б) - 3/11 * 0,4 - 0,4 * ( - 8/11); в) - 7/8 * 4/9 + 4/9 * 1/8; г) 2 2/9 * 3,7 - 2 2/9 * (-5,3); д) ( - 1 1/2 - 1 1/7) * 14; е) ( 2/5 - 3/4) * 20 решите по действиям плиз!!!!!!!!!​

Answer 1

Ответ:

$0.8 \times ( - 0.3) - 0.6 \times ( - 0.3) = (0.8 - 0.6) \times ( - 0.3) = 0.2 \times ( - 0.3) = - 0.06$

$- \frac{3}{11} \times 0.4 - 0.4 \times ( - \frac{8}{11} ) = ( - \frac{3}{11} - ( - \frac{8}{11} ) \times 0.4 = ( \frac{8}{11} - \frac{3}{11} ) \times 0.4 = \frac{5}{11} \times 0.4 = \frac{5}{11} \times \frac{2}{5} = \frac{2}{11}$

$- \frac{7}{8} \times \frac{4}{9} + \frac{4}{9} \times \frac{1}{8} = ( - \frac{7}{8} + \frac{1}{8} ) \times \frac{4}{9} = - \frac{6}{8} \times \frac{4}{9} = - \frac{3}{4} \times \frac{4}{9} = - \frac{1}{3}$

$2 \frac{2}{9} \times 3.7 - 2 \frac{2}{9} \times ( - 5.3) = (3.7 - ( - 5.3)) \times 2\frac{2}{9} = (3.7 + 5.3) \times \frac{20}{9} = \frac{9}{1} \times \frac{20}{9} = \frac{20}{1} = 20$

$( - \frac{11}{2} - \frac{11}{7} ) \times 14 = ( - \frac{77 + 22}{14} ) \times 14 = - \frac{99}{14} \times \frac{14}{1} = - \frac{99}{1} = - 99$

$( \frac{2}{5} - \frac{3}{4} ) \times 20 = ( \frac{8 - 15}{20} ) \times 20 = - \frac{7}{20} \times \frac{20}{1} = - \frac{7}{1} = - 7$