Giải thích các bước giải:
1) A= x^4-x^5
=> A= x^4( 1- x^5 )
2) B= -8x^2y^2 - 12xy^3 - 4xy^2
=> B= -4xy^2( 2x + 3y + 1 )
3) C= (x-y)^3 - x^3 + y^3
=> C= (x-y)^3 - (x^3 - y^3 )
<=> C= (x-y)^3 - (x-y)(x^2+xy+y^2)
<=> C= (x-y)((x-y)^2 - (x^2+xy+y^2))
<=> C= (x-y)(x^2 - 2xy + y^2 - x^2 - xy - y^2))
<=> C= (x-y)(-3xy)
4) D= 3x(x-y) - 2y(x-y)
=> D= (x-y)(3x-2y)
5) E= a(x+2) -2b(x+2) + (x+2)
=> E= (x+2)(a-2b+1)
6) G= 5x(x-y) - (y-x)
=>G= 5x(x-y) + (x-y)
<=> G= (x-y)(5x+1)
8) I= (x-1)^2 + y(1-x)
=> I= (x-1)^2 - y(x-1)
<=> I= (x-1)(x-1-y)
9) K= (x-2)^2- (2-x)^3
=> K= (x-2)^2 + (x-2)^3
=>K= (x-2)^2*(1+x-2) = (x-2)^2*(-1+x)
