-12x2 +19x +18 = 0
ax2 bx c = 0
a = -12
b = 19
c = 18
Δ = b2-4ac
Δ = 19² - (4 * -12 * 18)
Δ = 361 - (4*-216)
Δ = 361 - (-864)
Δ = 1225 Δ > 0
-12x2+19x+18=0
x = -b ∓ √Δ 2a
x' = -19 - √1225 2*-12 = -19 - 35.0 -24 = -54.0 -24 = 2.25
x" = -19 + √1225 2*-12 = -19 + 35.0 -24 = 16.0 -24 = -0.666666666667
x' = 324.0
x" = -96.0
S = {x ∈ R / x' = 324.0, x" = -96.0 }