-1x2 +15x -14 = 0
ax2 bx c = 0
a = -1
b = 15
c = -14
Δ = b2-4ac
Δ = 15² - (4 * -1 * -14)
Δ = 225 - (4*14)
Δ = 225 - (56)
Δ = 169 Δ > 0
-x2+15x-14=0
x = -b ∓ √Δ 2a
x' = -15 - √169 2*-1 = -15 - 13.0 -2 = -28.0 -2 = 14.0
x" = -15 + √169 2*-1 = -15 + 13.0 -2 = -2.0 -2 = 1.0
x' = 14.0
x" = 1.0
S = {x ∈ R / x' = 14.0, x" = 1.0 }