15 − x = 8
x = 7
15 − 7 = 8
8 = 8
13 − x = 7
x = 6
13 − 6 = 7
7 = 7
x + 40 = 47
x = 7
7 + 40 = 47
47 = 47
21 − x = 20
x = 1
21 − 1 = 20
20 = 20
14 − x = 7
x = 7
14 − 7 = 7
7 = 7
17 − x = 10
x = 7
17 − 7 = 10
10 = 10
15 − x = 5
x = 10
15 − 10 = 5
5 = 5
16 − x = 9
x = 7
16 − 7 = 9
9 = 9
27 − x = 20
x = 7
27 − 7 = 20
20 = 20
Ответ:
15 − x = 8
x + 40 = 47
14 − x = 7
17 − x = 10
16 − x = 9
27 − x = 20