-6x2 +13x -7 = 0

ax2 bx c = 0

a = -6

b = 13

c = -7

Δ = b2-4ac

Δ = 13² - (4 * -6 * -7)

Δ = 169 - (4*42)

Δ = 169 - (168)

Δ = 1      Δ > 0

-6x2+13x-7=0

x = -b ∓ √Δ 2a

x' = -13 - √1 2*-6 = -13 - 1.0 -12 = -14.0 -12 = 1.16666666667

x" = -13 + √1 2*-6 = -13 + 1.0 -12 = -12.0 -12 = 1.0

x' = 42.0

x" = 36.0

S = {x ∈ R / x' = 42.0, x" = 36.0 }