Question

1) (x – 7)(x + 8);
3)(a + 6) (4 - a);
5) (10 – c) (9 – c);

помогите пример​

Answer 1

1)

$(x - 7)(x + 8) = {x}^{2} + 8x - 7x - 56 = {x}^{2} + x + 56$

3)

$(a + 6)(4 - a) = 4a - {a}^{2} + 24 - 6a = - {a}^{2} - 2a + 24$

5)

$(10 - c)(9 - c) = 90 - 10c - 9c + {c}^{2} = {c}^{2} - 19c + 90$