-12x2 +19x -4 = 0

ax2 bx c = 0

a = -12

b = 19

c = -4

Δ = b2-4ac

Δ = 19² - (4 * -12 * -4)

Δ = 361 - (4*48)

Δ = 361 - (192)

Δ = 169      Δ > 0

-12x2+19x-4=0

x = -b ∓ √Δ 2a

x' = -19 - √169 2*-12 = -19 - 13.0 -24 = -32.0 -24 = 1.33333333333

x" = -19 + √169 2*-12 = -19 + 13.0 -24 = -6.0 -24 = 0.25

x' = 192.0

x" = 36.0

S = {x ∈ R / x' = 192.0, x" = 36.0 }