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

   =3(x-1)^2

b)=(x+3)(x^2-2x+4)

c)=(x^3-x)-(2x^2-2)

=x(x^2-1)-2(x^2-1)

=(x^2-1)(x-2)

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

d)=5^2-(4x)^2

=(5-4x)(5+4x)

e)=3x(x-2y)-6y(x-2y)

=3(x-2y)^2

a)=(a-2)(3/4m-3/4n)

b)=(a+6)^2

DT:bầy ong,đôi cánh,hoa,rừng,biển,đất

ĐT:rong ruổi,rù rì,nối,tìm

TT:ngọt ngào

=13,5

(2x^4-13x^3+15x^2+11x-3):(x^4-4x-3)=2x^2-5x+1

1.

a)xy-2y+5x-10=(xy-2y)+(5x-10)

=y(x-2)+5(x-2)

=(x-2)(y+5)

b)x^2-25y^2-6x+9=(x^2-6x+9)-25y^2

=(x-3)^2-(5y)^2

=(x-3-5y)(x-3+5y)

2.

a)

b)3x(x-5)-4x+20=0

<=>3x(x-5)-(4x-20)

<=>3x(x-5)-4(x-5)

<=>(x-5)(3x-4)

<=>x-5=0=>x=5 Hoặc 3x-4=0=>x=4/3

=(x^2+4x+4)-y^2

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

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

C.x3y+x2y-xy

=2x.3x-2x.1

=6x^2-2x