Разрешите уравнение 16-x^2-(4+x)^2=0

16-x^2-(16+8x+x^2)=0
16-x^2-16-8x-x^2=0
-2x^2-8x=0
2x^2+8x=0
2x(x+4)=0
2x=0; x+4=0
x=0; x=-4.

16 - x² -  (4+x)²  = 0
(4²  - x²)  - (4+x)²  = 0
(4+x)(4-x)  - (4+x)(4+x) =0
(4+x)* (4-x  - (4+x)) =0
(4+x)(4-x-4-x) = 0
(4+x)( - 2x) = 0
-2x * (4+x) = 0
-2x= 0
x₁ = 0
4+x=0
x₂ = - 4