НaстяРайская

25.01.2020 02:37 •  Алгебра

- = 2.117. Докажите тождество: 1) (x – 5)(x + 8) - (x + 4)(x - 1) = -36; 2) x4 – (x2 - 1) (x2 +1) = 1; 3) ** – (x2 – 7)(x2 + 7) = 49; 4) (x – 3)(x + 7) – (x + 5)(x - 1) = -16. — —