Question

помогите пожалуйста срочно решить дам 50 баллов ​

Answer 1

Ответ:

Пошаговое объяснение:

1)

х + 4/21 = 2/3 + 2/7

х + 4/21 = 14/21 + 6/21

х + 4/21 = 20/21

х = 20/21 - 4/21

х = 16/21

2)

у + 1/4 = 4/5 - 3/10

у + 5/20 = 16/20 - 6/20

у + 5/20 = 10/20

у = 10/20 - 5/20

у = 5/20

у = 1/4

3)

4/5 - х = 7/10 - 13/20

16/20 - х = 14/20 - 13/20

16/20 - х = 1/20

х = 16/20 - 1/20

х = 15/20

х = 3/4

4)

2/9 + х = 2/3 - 1/3

2/9 + х = 1/3

х = 1/3 - 2/9

х = 3/9 - 2/9

х = 1/9

Answer 2

$1)$

$x + \frac{4}{21} = \frac{2}{3} + \frac{2}{7} \\ x + \frac{4}{21} = \frac{14}{21} + \frac{6}{21} \\ x + \frac{4}{21} = \frac{20}{21} \\ x = \frac{20}{21} - \frac{4}{21} \\ x = \frac{16}{21}$

$2)$

$y + \frac{1}{4} = \frac{4}{5} - \frac{3}{10 } \\ y + \frac{5}{20} = \frac{16}{20} - \frac{6}{20} \\ y + \frac{5}{20} = \frac{10}{20} \\ y = \frac{5}{20} \\ y = \frac{1}{4}$

$3)$

$\frac{4}{5} - x = \frac{7}{10} - \frac{13}{20} \\ \frac{16}{20} - x = \frac{14}{20} - \frac{13}{20} \\ \frac{16}{20} - x = \frac{1}{20} \\ x = \frac{16}{20} - \frac{1}{20} \\ x = \frac{15}{20} \\ x = \frac{3}{4}$

$4)$

$\frac{2}{9} + x = \frac{2}{3} - \frac{1}{3} \\ \frac{2}{9} + x = \frac{1}{3} \\ x = \frac{1}{3} - \frac{2}{9} \\ x = \frac{3}{9} - \frac{2}{9} \\ x = \frac{1}{9}$