x³+2x²+x

= x ( x\(^2\) + 2x + 1 )

= x ( x + 1 )\(^2\)

a.

\(x^3-y^3+2x^2-2y^2\)

\(=\left(x-y\right)\left(x^2+xy+y^2\right)+\left(x-y\right)\left(2x+2y\right)\)

\(=\left(x-y\right)\left(x^2+xy+y^2+2x+2y\right)\)

b.

\(x^3+1-x^2-x\)

\(=\left(x+1\right)\left(x^2-x+1\right)-x\left(x+1\right)\)

\(=\left(x+1\right)\left(x^2-2x+1\right)\)

\(=\left(x+1\right)\left(x-1\right)^2\)

2x2 + 4x + 2 – 2y2 (có nhân tử chung là 2)

= 2.(x2 + 2x + 1 – y2) (Xuất hiện x2 + 2x + 1 là hằng đẳng thức)

= 2[(x2 + 2x + 1) – y2]

= 2[(x + 1)2 – y2] (Xuất hiện hằng đẳng thức (3))

= 2(x + 1 – y)(x + 1 + y)

\(a,a^2-2a-4b^2-4b\)

\(=\left(a^2-4b^2\right)-\left(2a+4b\right)\)

\(=\left(a-2b\right)\left(a+2b\right)-2\left(a+2b\right)\)

\(=\left(a+2b\right)\left(a-2b-2\right)\)

\(b,x^3-2x^2+4x-8\)

\(=x^2\left(x-2\right)+4\left(x-2\right)\)

\(=\left(x-2\right)\left(x^2+4\right)\)

\(c,x^3+36x-12x^2\)

\(=x^3-6x^2-6x^2+36x\)

\(=x^2\left(x-6\right)-6x\left(x-6\right)\)

\(=\left(x-6\right)\left(x^2-6x\right)\)

\(=x\left(x-6\right)^2\)

\(d,5a^2+3\left(a+b\right)^2-5b^2\)

\(=\left(5a^2-5b^2\right)+3\left(a+b\right)^2\)

\(=5\left(a^2-b^2\right)+3\left(a+b\right)^2\)

\(=5\left(a-b\right)\left(a+b\right)+3\left(a+b\right)^2\)

\(=\left(a+b\right)\left[5\left(a-b\right)+3\left(a+b\right)\right]\)

\(=\left(a+b\right)\left(5a-5b+3a+3b\right)\)

\(=\left(a+b\right)\left(8a-2b\right)\)

\(=2\left(a+b\right)\left(4a-b\right)\)

\(e,x^3-3x^2+3x-1-y^3\)

\(=\left(x^3-3x^2+3x-1\right)-y^3\)

\(=\left(x-1\right)^3-y^3\)

\(=\left(x-1-y\right)\left[\left(x-1\right)^2+\left(x-1\right)y+y^2\right]\)

\(=\left(x-y-1\right)\left(x^2-2x+1+xy-y+y^2\right)\)

\(=\left(x-y-1\right)\left(x^2+y^2-xy-y+1\right)\)

#Urushi☕

\(c.\\ x^3+36x-12x^2\\ =x\left(x^2-12x+36\right)\\ =x.\left(x^2-2.x.6+6^2\right)\\ =x.\left(x-6\right)^2\\ ---\\ d.\\ 5a^2+3\left(a+b\right)^2-5b^2\\ =\left(5a^2-5b^2\right)+3\left(a+b\right)^2\\ =5.\left(a^2-b^2\right)+3.\left(a+b\right)\left(a+b\right)\\ =5\left(a+b\right)\left(a-b\right)+3\left(a+b\right)\left(a+b\right)\\ =\left(a+b\right)\left(5a-5b+3a+3b\right)\\ =\left(a+b\right)\left(8a-2b\right)\\ =2\left(a+b\right)\left(4a-b\right)\)

\(e.\\ x^3-3x^2+3x-1-y^3\\ =\left(x-1\right)^3-y^3\\ =\left(x-1-y\right)\left[\left(x-1\right)^2+\left(x-1\right).y+y^2\right]\\ =\left(x-y-1\right).\left[\left(x^2-2x+1\right)+y\left(x+y-1\right)\right]\)

\(a.\\ a^2-2a-4b^2-4b\\ =\left(a^2-2a+1\right)-\left(4b^2-4b+1\right)\\ =\left(a-1\right)^2-\left(2b-1\right)^2\\ =\left[\left(a-1\right)+\left(2b-1\right)\right].\left[\left(a-1\right)-\left(2b-1\right)\right]\\ =\left(a+2b-2\right)\left(a-2b\right)\)

\(b.\\ x^3-2x^2+4x-8=x^2\left(x-2\right)+4\left(x-2\right)\\ =\left(x^2+4\right)\left(x-2\right)\)

b) \(16x-5x^2-3=5x\left(3-x\right)-\left(3-x\right)=\left(3-x\right)\left(5x-1\right)\)

c) \(2x^2+3x-5=2x\left(x-1\right)+5\left(x-1\right)=\left(x-1\right)\left(2x+5\right)\)

d) \(2x^2+3x-5=2x\left(x-1\right)+5\left(x-1\right)=\left(x-1\right)\left(2x+5\right)\)

`a) 8x^2 - 8xy - 4x + 4y`

`= 8x ( x - y ) - 4 ( x - y )`

`= ( x - y ) ( 8x - 4 )`

__________________________

`b) x^3 + 10x^2 + 25x - xy^2`

`=x ( x^2 + 10x + 25 ) - xy^2`

`= x ( x + 5 )^2 - xy^2`

`= x [ ( x + 5 )^2 - y^2 ]`

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

________________________________

`c) x^2 + x - 6`

`= x^2 + 3x - 2x - 6`

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

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

_______________________________

`d) 2x^2 + 4x - 16`

`= 2x^2 - 4x + 8x - 16`

`= 2x ( x - 2 ) + 8 ( x - 2 )`

`= ( x - 2 ) ( 2x + 8 )`

a) x2 + xy –x – y = x(x + y) – (x + y) = (x + y)(x -1 ).

b) a2 – b2 + 8a + 16 = (a2 + 8a + 16) – b2 = (a + 4)2 – b2

= (a + 4 – b)(a + 4 + b).

tui chỉ làm dc này thui

\(a,=8x\left(x-y\right)-4\left(x-y\right)\)

\(=\left(x-y\right)\left(8x-4\right)\)

\(a,x^2-2xy+y^2-z^2=\left(x-y\right)^2-z^2=\left(x-y-z\right).\left(x-y+z\right)\)

\(b,x^3+y^3+2x^2-2xy+2y^2=\left(x^3+y^3\right)+2\left(x^2-xy+y^2\right)=\left(x+y\right).\left(x^2-2xy+y^2\right)+2.\left(x^2-xy+y^2\right)=\left(x^2-xy+y^2\right).\left(x+y+2\right)\)