Question

Помогите доказать тождество!!!

Answer 1

$(4-x^2)(4+x^2)+2x^2(x^2-4)=(4-x^2)(4+x^2)-2x^2(4-x^2)= (4-x^2)(4+x^2-2x^2)=(4-x^2)((4-x^2)=(4-x^2)^2$