Question

Phân tích đa thức thành nhân tử

a) 6x² - 11x + 3

b) 2x² + 3x - 27

c) 2x² - 5xy - 3y²

Answer 1

a) 6x² - 11x + 3

= 6x² - 9x - 2x + 3

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

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

b ) 2x² + 3x - 27

= 2x² - 6x + 9x - 27

= 2x ( x - 3 ) + 9 ( x - 3 )

= ( x - 3 ) ( 2x + 9 )

c ) 2x² - 5xy - 3y²

= 2x² - 2xy - 3xy - 3y²

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

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

Answer 2

Ta có: 

a) 6x² - 11x +3 = 2x(3x-1)-3(3x-1)=(2x-3)(3x-1)

b) 2x² +3x - 27= x(2x+9)-3(2x+9)=(x-3)(2x+9)

c) 2x²  -5xy-3y² = 2x(x-3y)+y(x-3y)=(2x+y)(x-3y)