Question

Phân tích đa thức thành nhân tử

xy (x +y ) + yz (y +z ) xz +(x+z ) +2xyz

4x² - y² +4x +1

x³ - x +y³ - y

x³ - 3x² - 4x + 12

x⁴ - 5x² +4

(x+y+z )³ - x³ - y³ - z³

45 + x³ - 5x² - 9x

Answer 1

x⁴ - 5x² +4

=x⁴ -4x -x +4

=(x⁴ - 4x) - (x-4)

=x³(x-4)-(x -4)

=(x³ -1).(x-4)

Answer 2

3, x³ - x + y³ - y

=( x³ + y³) - (x + y)

=(x +y)(x² - xy +y²) -(x +y)

= x² - xy + y²

4, x³ - 3x² -4x +12

= (x³ - 3x²)-(4x -12)

=x²(x - 3) - 4(x - 3)

= (x² - 4)(x -3)

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

7, 45 +x³ - 5x² - 9x

=( x³ - 5x² )-( 9x - 45)

= x²(x-5)-9(x-5)

=( x²- 9)(x-5)

= (x-3)(x+3)(x-5)