Question

phân tích thành nhân tử
4x^3 - 4x^2 + x
x^2 - y^2 + 4 - 4x
x^2 -7x + 12

Answer 1

4x³ - 4x² + x

= x.(4x² - 4x + 1)

= x.[(2x)² - 2.2.x + 1²]

= x.(2x+1)²

x² - y² + 4 - 4x

= (x² - 4x) - (y² - 4)

= x.(x-4) - (y+4).(y-4)

x² - 7x + 12

= x² - 3x - 4x + 12

= x.(x-3) - 4.(x-3)

= (x-3).(x-4)

Answer 2

a) 4x³ - 4x² + x

= x(4x² - 4x + 1)

= x[(2x)² - 2.2x.1 + 1²)

= x(2x + 1)²

b) x² - y² + 4 - 4x

= (x² - 4x + 4) - y²

= (x² - 2.x.2 + 2²) - y²

= (x - 2)² - y²

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

c) x² - 7x + 12

= x² - 4x - 3x + 12

= (x² - 4x) - (3x - 12)

= x(x - 4) - 3(x - 4)

= (x - 4)(x - 3).