y = -2(x + 3)² + 32
y = -2(x² + 6x + 9) + 32
y = -2x² - 12x - 18 + 32
y = -2x² - 12x + 14
a = -2, b = -12, c = 14
Δ = b² - 4ac
Δ = (-12)² - 4 * (-2) * 14 = 144 + 112 = 256
√Δ = √256 = 16
x₁ = (-b - √Δ)/2a = (12 - 16)/(-4) = 1
x₂ = (-b + √Δ)/2a = (12 + 16)/(-4) = -7