Раскройте скобки:- (25 +a – 4b) =​

Пошаговое объяснение:

так как перед скобками стоит знак «-», то числа в скобках меняются на противоположные :

-(25 + а - 4b) = -25 - a + 4b

из10кг                                    кол-во  кг                                                           всего муки

9кг                                              40кг                                                                      ?кг

9кг                                               60кг                                                                      ?кг

9кг                                                100кг                                                                      ?кг

40/10*9=36-из 40 кг

60/10*9=54из  60кг

100/10*9=90 из 100кг

из10кг                                    кол-во  кг                                                           всего муки

9кг                                              40кг                                                                      ?кг

9кг                                               60кг                                                                      ?кг

9кг                                                100кг                                                                      ?кг

40/10*9=36-из 40 кг

60/10*9=54из  60кг

100/10*9=90 из 100кг