Jawab:

C. x² - x = 0

Penjelasan dengan langkah-langkah:

x² + 3x + 2 = 0

a = 1, b = 3, c = 2

x₁ + x₂ = -b/a = -3/1 = -3

x₁ . x₂ = c/a = 2/1 = 2

misal akar-akar persamaan kuadrat baru

p = x₁ + 2

q = x₂ + 2

p + q = x₁ + 2 + x₂ + 2

        = x₁ + x₂ + 4

        = -3 + 4

        = 1

p . q = (x₁ + 2)(x₂ + 2)

       = x₁ . x₂ + 2x₁ + 2x₂ + 4

       = x₁ . x₂ + 2(x₁ + x₂) + 4

       = 2 + 2(-3) + 4

       = 2 - 6 + 4

       = 0

Persamaan kuadrat baru:

x² - (p + q)x + p . q = 0

x² - x = 0