x2 x =0

-15x2 -19x +22 = 0

ax2 bx c = 0

a = -15

b = -19

c = 22

Δ = b2-4ac

Δ = -19² - (4 * -15 * 22)

Δ = 361 - (4*-330)

Δ = 361 - (-1320)

Δ = 1681      Δ > 0

-15x2-19x+22=0

x = -b ∓ √Δ 2a

x' = 19 - √1681 2*-15 = 19 - 41.0 -30 = -22.0 -30 = 0.733333333333

x" = 19 + √1681 2*-15 = 19 + 41.0 -30 = 60.0 -30 = -2.0

x' = 165.0

x" = -450.0

S = {x ∈ R / x' = 165.0, x" = -450.0 }