Question

phân tích đa thức thành nhân tử:

x⁶ - x⁴ - 9x³ + 9x²

Answer 1

x⁶ - x⁴ - 9x³ + 9x²

= x⁴.(x² - 1) - 9x².(x - 1)

= x⁴.(x - 1).(x + 1) - 9x².(x - 1)

= (x - 1).(x⁵ + x - 9x²)

= (x - 1).x.(x⁴ + 1 - 9x)

Answer 2

x^6-x^4-9x^3+9x^2

=x^2(x^4-x^2-9x+9)

=x^2[x^2(x^2-1)-9(x-1)]

=x^2[x^2(x-1)(x+1)-9(x-1)]

=x^2(x-1)[x^2(x+1)-9)]

=x^2(x-1)(x+1)(x^2-9)

=x^2(x-1)(x+1)(x-3)(x+3)