-12x2 +23x -5 = 0

ax2 bx c = 0

a = -12

b = 23

c = -5

Δ = b2-4ac

Δ = 23² - (4 * -12 * -5)

Δ = 529 - (4*60)

Δ = 529 - (240)

Δ = 289      Δ > 0

-12x2+23x-5=0

x = -b ∓ √Δ 2a

x' = -23 - √289 2*-12 = -23 - 17.0 -24 = -40.0 -24 = 1.66666666667

x" = -23 + √289 2*-12 = -23 + 17.0 -24 = -6.0 -24 = 0.25

x' = 240.0

x" = 36.0

S = {x ∈ R / x' = 240.0, x" = 36.0 }