Question

 

Phân tích đa thức thành nhân tử 

1) 27x^3 - a^3b^3

2) 1 - x^2y^4

3) (3x -2y)^2 - (2x - 3y)^2

Answer 1

1. = (3x)³ - (ab)³

= (3x - ab)[(3x)² + 3x . ab + ab²)

= (3x - ab)(9x² + 3xab + ab²)

Answer 2

2. 1 - x²y⁴

= 1² - (xy²)²

= (1 - xy²)(1 + xy²)

Answer 3

3.  (3x - 2y)² - (2x - 3y)²

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

= (x - 5y)(5x - 5y)