-1x2 +14x -13 = 0
ax2 bx c = 0
a = -1
b = 14
c = -13
Δ = b2-4ac
Δ = 14² - (4 * -1 * -13)
Δ = 196 - (4*13)
Δ = 196 - (52)
Δ = 144 Δ > 0
-x2+14x-13=0
x = -b ∓ √Δ 2a
x' = -14 - √144 2*-1 = -14 - 12.0 -2 = -26.0 -2 = 13.0
x" = -14 + √144 2*-1 = -14 + 12.0 -2 = -2.0 -2 = 1.0
x' = 13.0
x" = 1.0
S = {x ∈ R / x' = 13.0, x" = 1.0 }