a) 5x⁴y³ - 15x³y²
= 5x³y².(x - 3)
b) 8x³ - 64y³
= 8.(x³ - 8y³)
= 8.(x - 2y)(x² + 2y + 4)
c) x² + 3x + 3y - y²
= (x² - y²) + (3x + 3y)
= (x - y)(x + y) + 3(x + y)
= (x + y)(x - y + 3)
d) Sửa đề:
3(2x - y) + 4x² - 9
= 3(2x - y) + (4x² - 9)
= 3(2x - y) + (2x - y)(2x + y)
= (2x - y)(2x + y + 3)