\(8x^4y+12x^2y^2+20x^3y^3\)

\(=4x^2y\left(2x^2+3y+5xy^2\right)\)

\(=x^2y\left(8x^2+12y+20xy^3\right)\)

`8x^4y+12x^2y^2+20x^3y^4=4x^2y (2x^2+3y+5xy^3)`

`4x^2-1`

`=(2x)^2-1`

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

`125x^3+1`

`=(5x)^3+1`

`=(5x+1)(25x^2-5x+1)`

`x^4+2x^2+1`

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

`4x^2-12xy+y^2`

`=4x^2-12xy+9y^2-8y^2`

`=(2x-3y)^2-(2sqrt2y)^2`

`=(2x-2sqrt2y-3y)(2x+2sqrt2y-3y)`

\(a.6x^3-9x^2=3x^2\left(2x-3\right)\\ b.20x^2y-12x^3=4x^2\left(5y-3x\right)\)

a) \(6x^3-9x^2=3x^2\left(2x-3\right)\)

b) \(20x^2y-12x^3=4x^2\left(5y-3x\right)\)

a: \(6x^3-9x^2=3x^2\left(2x-3\right)\)

b: \(20x^2y-12x^3=4x^2\left(5y-3x\right)\)

a)  \(4x^2+20x+25=\left(2x+5\right)^2\)

b) \(x^2-6x+9=\left(x-3\right)^2\)

c) \(4x^2+12x+9=\left(2x+3\right)^2\)

\(15\left(x-y\right)-20x\left(y-x\right)=\left(15+20x\right)\left(x-y\right)=5\left(3+4x\right)\left(x-y\right)\)

\(15\left(x-y\right)-20x\left(y-x\right)\)

\(=15\left(x-y\right)+20x\left(x-y\right)\)

\(=5\left(x-y\right)\left(3+4x\right)\)

\(5\left(x^2+y^2\right)^2-20x^2y^2\)

\(=5x^4+5y^4-10x^2y^2\)

\(=5\left(x^2-y^2\right)^2\)

\(=5\left(x-y\right)^2\cdot\left(x+y\right)^2\)

Lời giải:

$5(x^2+-y^2)^2-20x^2y^2=5(x^2-y^2)^2-20x^2y^2$

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