persamaan x^3-3x²-x+A=0 mempunyai 2 akar yg saling berlawanan maka tentukan A nilai A B akar2 persamaan Tolong pakai caranya ya

x³ - 3x² - x + A = 0,
a=1, b = - 3, c = -1 , d = A
akar akar x₁, x₂, x₃
x₁ = - x₂
x₁ + x₂ = 0

(x₁+ x₂)+ x₃ = -b/a
0 + x₃ = -(-3)/1
x₃ = 3

x₁x₂+ x₁x₃+ x₂x₃ = c/a = -1/a = -1
x₁x₂ + (x₁+x₂)x₃ = 1
x₁x₂ +(0)(3) = -1
x₁ x₂  = -1

x₁x₂x₃  = d/a
(-1)(3) = A/1
A= -3

x₁ = -x₂
x₁x₂ = -1
-x₂² = -1
x₂= 1
x₁ = -1
x₃ = 3