-18x2 +2x +16 = 0
ax2 bx c = 0
a = -18
b = 2
c = 16
Δ = b2-4ac
Δ = 2² - (4 * -18 * 16)
Δ = 4 - (4*-288)
Δ = 4 - (-1152)
Δ = 1156 Δ > 0
-18x2+2x+16=0
x = -b ∓ √Δ 2a
x' = -2 - √1156 2*-18 = -2 - 34.0 -36 = -36.0 -36 = 1.0
x" = -2 + √1156 2*-18 = -2 + 34.0 -36 = 32.0 -36 = -0.888888888889
x' = 324.0
x" = -288.0
S = {x ∈ R / x' = 324.0, x" = -288.0 }