1) ( 4x - 3y )^2 = 16x^2 - 24xy + 9y^2
2) ( 2x + y )( 3x - 5y ) = 6x^2 - 10xy + 3xy - 5y^2 = 6x^2 - 7xy - 5y^2
3) - ( 6x^2 - 7xy - 5y^2 ) = - 6x^2 + 7xy + 5y^2
4) 16x^2 - 24xy + 9y^2 - 6x^2 + 7xy + 5y^2 = 10x^2 - 17xy + 14y^2
Ответ 10х^2 - 17хy + 14y^2