ГДЗ Математика 7 клас Істер (2024)

Виконайте множення:

1) (c + 7)(7 – c) = (7 + c)(7 – c) = 49 – c2;
2) (0,5m – 3)(0,5m + 3) = 0,25m2 – 9;
3) (3k + 7)(3k – 7) = 9k2 – 49;
4) (2р – 9q)(9q + 2p) = (2p – 9q)(2p + 9q) = 4p2 – 81q2;
5) (10m + 9n)(9n – 10m) = (9n + 10m)(9n – 10m) = 81n2 – 100m2;
6) (2/3c – 4/5d)( 2/3c + 4/5d) = (2/3c)2 – (4/5d)2 = 4/9c2 – 16/25d2.