Mọi người giúp mình với

`1) ( x + 4 )^2 + ( x + 5 )( x - 5 ) - 2x( x + 1 )`

`= x^2 + 8x + 16 + x^2 - 25 - 2x^2 - 2x`

`= 6x - 9`

`2) ( x- 1 )^2 - ( x - 4 )( x+ 4 ) + ( x + 3 )^2`

`= x^2 - 2x + 1 - x^2 + 16 + x^2 + 6x + 9`

`= 4x + 26`

`3) ( x - 1 )^2 - 2( x - 3 )( x + 3 ) + 4x( x - 4 )`

`= x^2 - 2x + 1 - 2( x^2 - 9 ) + 4x^2 - 16x`

`= 5x^2 - 18x + 1 - 2x^2 + 18`

`= 3x^2 - 18x + 19`

`4) ( y - 3 )( y + 3 )( y^2 + 9 ) - ( y^2 + 2 )( y^2 - 2 )`

`= ( y^2- 9 )( y^2 + 9 ) - ( y^2 + 2 )( y^2 - 2) `

`= ( y^4 - 81 ) - ( y^4 - 4 )`

`= y^4 - 81 - y^4 +4`

`= - 77`

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

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

`= ( 2x + 2 )^2`

`2) ( 3x - 2y )^2 + 4( 3x - 2y ) + 4`

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

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

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

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

`= 5^2`

`= 25`

`4) ( 3x - 5 )^2 - 2( 3x - 5 )( 3x + 5 ) + ( 3x + 5 )^2`

`= ( 3x - 5 - 3x - 5 )^2`

`= ( -10 )^2`

`= 100`

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

`= 9x^2 + 12x + 4 + 16x^2 - 8x + 1 + 4 - 25x^2`

`= 4x + 9`

`6) ( x + y -z )^2 + 2( x + y - z )( z - y) + ( z - y )^2`

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

`= x^2`