15x2 -18x +3 = 0
ax2 bx c = 0
a = 15
b = -18
c = 3
Δ = b2-4ac
Δ = -18² - (4 * 15 * 3)
Δ = 324 - (4*45)
Δ = 324 - (180)
Δ = 144 Δ > 0
15x2-18x+3=0
x = -b ∓ √Δ 2a
x' = 18 - √144 2*15 = 18 - 12.0 30 = 6.0 30 = 0.2
x" = 18 + √144 2*15 = 18 + 12.0 30 = 30.0 30 = 1.0
x' = 45.0
x" = 225.0
S = {x ∈ R / x' = 45.0, x" = 225.0 }