Giúp mik với mình cần gấp ạ

Đáp án:

Giải thích các bước giải:

`1) x² - 2x + 1 = ( x - 1 )²`

`2) x² + 4x + 4 = ( x + 2 )²`

`3) 9x² + 6x + 1 = ( 3x + 1 )²`

`4) 4x² + 4x + 1 = ( 2x + 1 )²`

`5) x^4 - 8x² + 16 = ( x² - 4 )²`

`= [ ( x + 2 )( x - 2 ) ]²`

`6) x² + x + 1/4 = ( x + 1/2 )²`

`7) 64y^4 + 16xy² + x²`

`= ( 8y² )² + 2 . 8y² . x + x²`

`= ( x + 8y² )²`

`8) 1/(25)x² - 4xy³ + 100y^6`

`= ( 1/5x )² - 2 . 1/5x . 10y³ + ( 10y³ )²`

`= ( 1/5x + 10y³ )²`

`9) 27 + 27x + 9x² + x³`

`= x³ + 3 . x² . 3 + 3 . x . 3² + 3³`

`= ( x + 3 )³`

`10) 8x³ - 12x² + 6x - 1`

`= ( 2x )³ - 3 . ( 2x )² . 1 + 3 . 2x . 1 - 1³`

`= ( 2x - 1 )³`

`11) 8x³ + 12x²y + 6xy² + y³`

`= ( 2x )³ + 3 . ( 2x )² . y + 6 . 2x . y² + y³`

`= ( 2x + y )³`

`12) 8y^6 + 36xy^4 + 54x²y² + 27x³`

`= ( 2y² )³ + 3 . ( 2y )² . 3x + 3 . 2y² . ( 3x )² + ( 3x )³`

`= ( 2y² + 3x )³`

`13) x³ - 3x² + 3x - 1 = ( x - 1 )³`

`14) 8 - 36x + 54x² - 27x³`

`= 2³ - 3 . 2² . 3x + 3 . 2 . ( 3x )² - ( 3x )³`

`= ( 2 - 3x )³`

`15) 9x² - 4 = ( 3x + 2 )( 3x - 2 )`

`16) 1/(100)y^4 - x² = ( 1/(10)y² - x )( 1/(10)y² + x )`

`18) 4x² - 1/(25) = ( 2x + 1/5 )( 2x - 1/5 )`

`19) 4 - 25x² = ( 2 + 5x )( 2 - 5x )`

`20) y² - 9x² = ( y + 3x )( y - 3x )`