Question

Помогите

(3 - а) * (3 + a) - 9 + a²

Answer 1

9+3a-3a-a^2-9+a^2= 0

Answer 2

(3 - а) × (3 + a) - 9 + a² = (9-а²) -9+а² = 9-а²-9+а² = 0