`@Enami  Asa`

`1,`

`x^3+2x^2+x`

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

`=x(x+1)^2`

`2,`

`x^4+4x^3+4x^2`

`=x^2(x^2+4x+4)`

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

`4,`

`2x^3-12x^2+18x`

`=2x(x^2-6x+9)`

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

`5,`

`8x^2y-8xy+2x`

`=2x(4xy-4y+1)`

`7,`

`2x^2+5x^3+x^2y`

`=x^2(2+5x+y)`

`8,`

`2x^3y-8x^2y+8xy`

`=2xy(x^2-4xy+4)`

`10,`

`6x^2y^2+4xy^2-12x^3y`

`=2xy(3xy+2y-6x^2)`

`11,`

`2x^2y-3xy^2+4x^2y^2`

`=xy(2x-3y+4xy)`

`13,`

`2x^3y^4-4x^5y^6+6y^7x^8`

`=2x^3y^4(1-2x^2y^2+3y^3x^5)`

`14,`

`2x^4y^3-3x^2y^4+5x^3y^4`

`=x^2y^2(2x^2y-3y^2+5xy^2)`