Question

последнее пожалуйста..

Answer 1

вооот .............вдцщцщ

Answer 2

1) (x - 7)(x + 3) = x^2 + 3x - 7x - 21 = x^2 - 4x - 21
2) (8 - a)(8 + a) - (a^2 + 4) = (64 + 8a - 8a - a^2) - (a + 2)(a + 2) = 
(64 - a^2) - (a^2 + 2a + 2a + 4) = 64 - a^2 - a^2 - 4a - 4 = 60 - 2a^2 - 4a
3) (x^2 - xy + y^2)(x + y) = x^3 + y^3
 (x + 2)(x + 1) - (x + 4)(x + 3) = 0
(x^2 + x + 2x + 2) - (x^2 + 3x + 4x + 12) = 0
x^2 + 3x + 2 - x^2 - 7x - 12 = 0
-4x - 10 = 0
-4x = 10
x = -10/4 = -2.5