5x2 +2x -3 = 0
ax2 bx c = 0
a = 5
b = 2
c = -3
Δ = b2-4ac
Δ = 2² - (4 * 5 * -3)
Δ = 4 - (4*-15)
Δ = 4 - (-60)
Δ = 64 Δ > 0
5x2+2x-3=0
x = -b ∓ √Δ 2a
x' = -2 - √64 2*5 = -2 - 8.0 10 = -10.0 10 = -1.0
x" = -2 + √64 2*5 = -2 + 8.0 10 = 6.0 10 = 0.6
x' = -25.0
x" = 15.0
S = {x ∈ R / x' = -25.0, x" = 15.0 }