-15x2 +13x -2 = 0
ax2 bx c = 0
a = -15
b = 13
c = -2
Δ = b2-4ac
Δ = 13² - (4 * -15 * -2)
Δ = 169 - (4*30)
Δ = 169 - (120)
Δ = 49 Δ > 0
-15x2+13x-2=0
x = -b ∓ √Δ 2a
x' = -13 - √49 2*-15 = -13 - 7.0 -30 = -20.0 -30 = 0.666666666667
x" = -13 + √49 2*-15 = -13 + 7.0 -30 = -6.0 -30 = 0.2
x' = 150.0
x" = 45.0
S = {x ∈ R / x' = 150.0, x" = 45.0 }