Tentukan nilai x yang memenuhi |2×-3|² – |2×-3| ≥ 20

|2x-3|^2-|2x-3| ≥20
(2x-3)^2-|2x-3| ≥20
4x^2-12x+9-|2x-3| ≥20
4x^2-12x-|2x-3| ≥20-9
4x^2-12x-|2x-3| ≥11
4x^2-12x-(2x-3) ≥11,2x-3 ≥0
4x^2-12x-(-(2x-3)) ≥11,2x-3<0
x ∈<-∞, 1/2] U [4,+ ∞>, x ≥3/2
x ∈<-∞,-1] U [7/2,+ ∞>,x<3/2
x ∈[4+∞>
x ∈<-∞,-1]

∈<-∞,1] U [4,+ ∞>