Răspuns:
(5x - 1)/2 = 1
5x - 1 = 2
5x = 2 + 1
5x = 3
x = 3/5 ∉ Z
sau
5x - 1/2 = 1
10x - 1 = 2
10x = 3
x = 3/10 ∉ Z