a) 2 x-1 ≥5
2x≥5+1
2x≥6
x≥6/2
x≥3
x∈[3,+α)
S={3,4,5,6,...............}
b) 2 x+3≥-9
2x≥-9-3
2x≥-12
x≥-12/2
x≥-6
x∈[-6,+α)
S={-6,α-5,-4,-3,-2,-1,0,1.....}
c) 3 x - 1 ≥ 8
3x≥8+1
3x≥9
x≥9/3
x≥3
x∈[3,+α)
S={3,4,α5...............}
d) 4 x+1 < 9
4x<9-1
4x<8
x<8/4
x<2
x∈(-α,2)
S={............-2,-1,0,1)