Đáp án:

Giải thích các bước giải:

 ` 1. `

` 1) ( 3x - 2 )( -x ) - ( -2x )^2  `

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

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

` = -7x^2 + 2x `

` 3) 3x( xy^2 - y ) - ( xy + 1 )( 1 - xy ) `

` = ( 3x^2y^2 - 3xy ) - ( 1 - x^2y^2 ) `

` = 3x^2y^2 - 3xy - 1 + x^2y^2 `

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

` = 4x^2y^2 - 3xy - 1 `

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

` = ( 4x^2 + 4x + 1 ) + ( 9 - 6x + x^2 ) - 2( 6x - 2x^2 - 3 + x ) `

` = 4x^2 + 4x + 1 + 9 - 6x + x^2 - 2( -2x^2 + 7x - 3 ) `

` = 4x^2 + 4x + 1 + 9 - 6x + x^2 + 4x^2 - 14x + 6 `

` = ( 4x^2 + x^2 + 4x^2 ) + ( 4x - 6x - 14x ) + ( 1 + 9 + 6 ) `

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

` 7) ( x - 1 )( x + 1 )( x^2 + 1 )( x^4 + 1 )( x^8 + 1 ) `

` = ( x^2 - 1 )( x^2 + 1 )( x^4 + 1 )( x^8 + 1 ) `

` = ( x^4 - 1 )( x^4 + 1 )( x^8 + 1 ) `

` = ( x^8 - 1 )( x^8 + 1) `

` = x^16 -1 `

$#love-ends $