\(x^2+4xy-4z^2+4y^2\)

\(=x^2+4xy+4y^2-4z^2\)

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

\(=\left(x+2y-2z\right)\left(x+2y+2z\right)\)

\(x^2+2x-15\)

\(=x^2+2x+1-16\)

\(=\left(x+1\right)^2-16\)

\(=\left(x+1-4\right)\left(x+1+4\right)\)

\(=\left(x-3\right)\left(x+5\right)\)

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

c

c

\(x^2+4xy-9+4y^2\)

\(=\left(x^2+4xy+4y^2\right)-9\)

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

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

\(=\left(x+2y\right)^2-9=\left(x+2y-3\right)\left(x+2y+3\right)\)

Đề bài yêu cầu gì thế em?

`x^2 +4xy+ 4y^2 -9`

`= (x^2 + 2x.2y + 4y^2) -9`

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

`= (x+2y  -3)(x+2y +3)`

x² + 4xy + 4y² - 9 

= (x² + 4xy + 4y²)-3²

= (x+2y)² - 3²

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

\(x^2+4y^2-4xy-4\)

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

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

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

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

a) 2x²-4xy+2y²
= 2x²-2xy-2xy+2y²
= 2x(x-y)-2y(x-y)
= (2x-2y)(x-y)
b) x²+4xy+4y²-9
= (x+2y)²-3²
= (x+2y-3)(x+2y+3)
c) x⁴-x³y+x-y
= x³(x-y)+(x-y)
= (x³+1)(x-y)

\(a,=2\left(x^2-2xy+y^2\right)=2\left(x-y\right)^2\\ b,=\left(x+2y\right)^2-9=\left(x+2y-3\right)\left(x+2y+3\right)\\ c,=x^3\left(x-y\right)+\left(x-y\right)\\ =\left(x+1\right)\left(x-y\right)\left(x^2-x+1\right)\)