-9x2 +13x +10 = 0
ax2 bx c = 0
a = -9
b = 13
c = 10
Δ = b2-4ac
Δ = 13² - (4 * -9 * 10)
Δ = 169 - (4*-90)
Δ = 169 - (-360)
Δ = 529 Δ > 0
-9x2+13x+10=0
x = -b ∓ √Δ 2a
x' = -13 - √529 2*-9 = -13 - 23.0 -18 = -36.0 -18 = 2.0
x" = -13 + √529 2*-9 = -13 + 23.0 -18 = 10.0 -18 = -0.555555555556
x' = 162.0
x" = -45.0
S = {x ∈ R / x' = 162.0, x" = -45.0 }