Question

УПРАЖНЕНИЯ для повтОРЕНИЯ КУРСА МАТЕМАТИКИ для 7 КЛАССОВ7)Выполните действия (1-3):1) 3.1/9÷2.1/3-2.5/62) 1.5/7-4.1/13÷1.19/263)10.16/17÷8.5/11+1.2/3​4)47/48:3.13/27-13/16​

Answer 1

Ответ:

Объяснение:

...............

Answer 2

1) 3.1/9 ÷ 2.1/3 - 2.5/6

To solve this, we first need to convert the mixed numbers to improper fractions: 3.1/9 = (3*9 + 1)/9 = 28/9 2.1/3 = (2*3 + 1)/3 = 7/3 2.5/6 = (2*6 + 5)/6 = 17/6

Now we can perform the division and subtraction: 28/9 ÷ 7/3 - 17/6 = 28/9 * 3/7 - 17/6 = 84/63 - 17/6 = 84/63 - 182/63 = -98/63

So the answer to the first problem is -98/63.

2) 1.5/7 - 4.1/13 ÷ 1.19/26

Convert the mixed numbers to improper fractions: 1.5/7 = 11/7 4.1/13 = 53/13 1.19/26 = 45/26

Now we can perform the division and subtraction: 11/7 - 53/13 ÷ 45/26 = 11/7 - 53/13 * 26/45 = 11/7 - 1378/585 = 785/585 - 1378/585 = -593/585

So the answer to the second problem is -593/585.

3) 10.16/17 ÷ 8.5/11 + 1.2/3

Convert the mixed numbers to improper fractions: 10.16/17 = (10*17 + 16)/17 = 186/17 8.5/11 = (8*11 + 5)/11 = 93/11 1.2/3 = (1*3 + 2)/3 = 5/3

Now we can perform the division and addition: 186/17 ÷ 93/11 + 5/3 = 186/17 * 11/93 + 5/3 = 2046/1551 + 5/3 = 2046/1551 + 2583/1551 = 4629/1551 = 3

So the answer to the third problem is 3.

4) 47/48 ÷ 3.13/27 - 13/16

Convert the mixed number to improper fraction: 3.13/27 = (3*27 + 13)/27 = 94/27

Perform the division and subtraction: 47/48 ÷ 94/27 - 13/16 = 47/48 * 27/94 - 13/16 = 1269/4512 - 1722/4512 = -453/4512

So the answer to the fourth problem is -453/4512.