Question

a) 12 < x - 3 < 27
b) 123 < x - 100 < 129

Answer 1

a) 12<x-3<27 I +3
    15<x<30
    x∈{16,17,18,19,20,21,22,23,24,25,26,27,28,29}

b)  123<x-100<129 I +100
      223<x<229
      x∈{224,225,226,227,228}