a) x + 13.6 < 17.4
x < 17.4 - 13.6
x < 3.8
x ∈ {3,2,1,0}
b) 3,2x < 12.7
x < 12.7 : 3.2
x < 3.9
x ∈ {3,2,1,0}
c) 18.4 - x < 12.7
-x < 12.7 - 18.4
-x < -5.7 / · - 1
x > 5.7
x ∈ {6,7,8......(infinit)}
d) x - 7.9 < 10.3
x < 10.3 + 7.9
x < 18.2
x ∈ {18,17,16,15....3,2,1,0}
e) 7.8x > 12.2
x > 12.2 : 7.8
x > 1.56
x ∈ {2,3,4,5....(infinit)}