5x2 -7x +2 = 0
ax2 bx c = 0
a = 5
b = -7
c = 2
Δ = b2-4ac
Δ = -7² - (4 * 5 * 2)
Δ = 49 - (4*10)
Δ = 49 - (40)
Δ = 9 Δ > 0
5x2-7x+2=0
x = -b ∓ √Δ 2a
x' = 7 - √9 2*5 = 7 - 3.0 10 = 4.0 10 = 0.4
x" = 7 + √9 2*5 = 7 + 3.0 10 = 10.0 10 = 1.0
x' = 10.0
x" = 25.0
S = {x ∈ R / x' = 10.0, x" = 25.0 }