18193. какую часть целого составляет часть? а) 200 грамм от тонны; б) 35 секунд от минуты, в) 5 см от метра.​

henry ford (1863-1947) pipeline to serve the people today can hardly find a person who does not know the name of henry ford - one of the automobile "kings". machines produced in many plants of the company "ford", flying through the streets of almost all the cities of the world, including russia. henry's interest in technology has become evident since childhood. his sister margaret recalled: "when we were given at christmas, mechanical toys, we have always said: do not let them henry! he just disassemble them for parts to pieces. " children's abilities have led to the fact that adult ford started organizing the production of cars. and although his work in guiding henry ford showed great ability and will of iron, the first two firms have burst - not enough experience. in 1913, in a difficult position, and the third was - she could not cope with the increased volume of orders. and here at ford appeared a great idea whose implementation meant a real breakthrough in the industry. the fact is that while assembling a vehicle carried by the same displacement, which itself perform all necessary operations. with this approach, the car was built for a long time and was very expensive. ford broke the weight of the assembly process by a series of successive operations, and each of them requested a separate working. it turned out that the whole team did a factory car. labour productivity has increased. and she jumped quite sharply when ford decided to replace the low table to be assembled on a moving belt - so there was a first belt! ford company has significantly increased and, importantly, reduce the cost of production of its vehicles. now they were able to buy a family of moderate means. the competitors were far behind. well, henry ford wrote his name into the history of the industry on the planet!

Пошаговое объяснение:

   1 . 3x² - 5x - 4 + 2x + x² + 3x - 1 = 4x² - 5 ;

  якщо  х = 1/2 , то   4x² - 5 = 4 * ( 1/2 )² - 5 = 1 - 5 = - 4 .

   2 . Нехай  туристи подолали  х км шляху .

          1) 5/9 x  км - проїхали автомобілем ;

          2)  х - 5/9 х = 4/9 х ( км ) -  залишок шляху ;

          3)  3/4 * 4/9 х = 1/3 х ( км ) - пропливли на човні .

    Рівняння :    х - ( 5/9 х + 1/3 х ) = 5 ;

                          х - 8/9 x = 5 ;

                                1/9 x = 5 ;

                                x = 5 : 1/9 ;

                                x = 45 км  - це відповідь .

   3 .   - 3y² + 6yt - 4t - 2yt - t + y² - 4yt = - 2y² - 5t ;

       якщо  y = - 1  , t = 2/5 , то  - 2y² - 5t = -2 * (- 1 )² - 5 * 2/5 = - 2 - 2 = - 4 .    

Пошаговое объяснение:

3х² - 5х - 4 + 2х + х² + 3х - 1 = 4х² - 5

4 * (1/2)² - 5 = 4 * 1/4 - 5 =

4/4 - 5 = 1 - 5 = -4

ответ: -4

Номер 2

Весь путь = х км

На авто = 5/9х км

На лодке = 3/4 * (х - 5/9х) = 3/4 * 4/9х = 12/36х = 1/3х км

Пешком = 5 км

5/9х + 1/3х + 5 = х

5/9х + 3/9х + 5 = х

8/9х + 5 = х

8/9х - х = -5

-1/9х = -5

х = -5 : (-1/9)

х = -5 * (-9/1)

х = 45/1

х = 45

Весь путь = (х) = 45 км

На авто = (5/9х) = 5/9 * 45 = 5/1 * 5 = 25/1 = 25 км

На лодке = (1/3х) = 1/3 * 45 = 45/3 = 15 км

Пешком = 5 км

25 + 15 + 5 = 45

Номер 3

-3у² + 6уt - 4t - 2yt - t + y² - 4yt = -2y² - 5t

-2 * (-1)² - 5 * 2/5 =

-2*1 - 10/5 = -2 - 2 = -4