Question

Помогите пожалуйста: (x - 7) (x + 8) (9 - y) (y + 5) (a + 6) (4 - a) (2 - b) (b + 3) (10 - c) (9 - c) (d + 3) (d + 11)

Answer 1

1)
${ x}^{2} + 8x - 7x - 56 = { x}^{2} + x - 56$