Question

Помогите пожалуйста даю 20 баллов срочно

Answer 1

$(a + 1)(a - b) = {a}^{2} - ab + a - b$

$- (a + 1)(a - b) = (a + 1)(b - a) = ab - {a}^{2} + b - a = - {a}^{2} + ab - a + b$

$- (4x + 1)(x - 3) = (4x + 1)(3 - x) = 12x - 4 {x}^{2} + 3 - x = \\ \\ = - 4 {x}^{2} + 11x + 3$

$- (4 - y)(y - 11) = (y - 4)(y - 11) = {y}^{2} - 11y - 4y + 44 = \\ \\ = {y}^{2} - 15y + 44$

$- (x - y)( {x}^{2} + {y}^{2} ) = (y - x)( {x}^{2} + {y}^{2} ) = {x}^{2} y + {y}^{3} - {x}^{3} - x {y}^{2} = \\ \\ = - {x}^{3} - x {y}^{2} + {x}^{2} y + {y}^{3}$

$- (2 {m}^{2} - 2 {n}^{2} )( {m}^{2} + {n}^{2} ) = (2 {n}^{2} - 2 {m}^{2} )( {m}^{2} + {n}^{2} ) = \\ \\ = 2 {n}^{2} {m}^{2} + 2 {n}^{4} - 2 {m}^{4} - 2 {m}^{2} {n}^{2} = 2 {n}^{4} - 2 {m}^{4}$