1) (1 / 7) * x = 1
x = 1 / (1 / 7)
x = 1 * (7 / 1)
x = 7
2) 9 * x = 1
x = 1 / 9
3) (1 + (5 / 8)) * x = 1
(8 / 8 + 5 / 8) * x = 1
(13 / 8) * x = 1
x = 1 / (13 / 8)
x = 1 * (8 / 13)
x = 8 / 13
4) (1 / 2) * x = 1
x = 1 / (1 / 2)
x = 1 * (2 / 1)
x = 1 * 2
x = 2
5) 5 * x = 1
x = 1 / 5
6) (1 / 10) * x = 1
x = 1 / (1 / 10)
x = 1 * (10 / 1)
x = 10
7) (3 + (2 / 5)) * x = 1
(15 / 5 + 2 / 5) * x = 1
(17 / 5) * x = 1
x = 1 / (17 / 5)
x = 5 / 17
8) 100 * x = 1
x = 1 / 100
5 звездочек поставьте уж