-12x2 +19x -7 = 0
ax2 bx c = 0
a = -12
b = 19
c = -7
Δ = b2-4ac
Δ = 19² - (4 * -12 * -7)
Δ = 361 - (4*84)
Δ = 361 - (336)
Δ = 25 Δ > 0
-12x2+19x-7=0
x = -b ∓ √Δ 2a
x' = -19 - √25 2*-12 = -19 - 5.0 -24 = -24.0 -24 = 1.0
x" = -19 + √25 2*-12 = -19 + 5.0 -24 = -14.0 -24 = 0.583333333333
x' = 144.0
x" = 84.0
S = {x ∈ R / x' = 144.0, x" = 84.0 }