Question

Phân tích thành nhân tử :

a) 5x^2 + 5xy - x - y                                                                                                     b) 7x - 6x^2 - 2 .

Answer 1

a) 5x^2 + 5xy - x - y 

=5x.(x+y)-(x+y)

=(x+y)(5x-1)

b) 7x - 6x^2 - 2

=-6x²+3x+4x-2

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

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

Answer 2

(x−5)2−16 

=(x−5)2−42 

=(x−5+4)(x−5−4) 

=(x−1)(x−9) 




25−(3−x)2 

=52−(3−x)2 

=(5−3+x)(5+3−x) 

=(x+2)(8−x) 




(7x−4)2−(2x+1)2 

=(7x−4+2x+1)(7x−4−2x−1) 

=(9x−3)(5x−5) 

=15(3x−1)(x−1) 

Answer 3

a. 5x²+5xy-x-y

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

= (x+y)(5x+1)

b. 7x-6x²-2

= -6x²+7x-2

= -6x²+3x+4x-2

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

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