Докажите тождество (9/(x+3)²+18/x²-9+9/(x-3)²)*(x/3-3/x)²=4

Question

Докажите тождество (9/(x+3)²+18/x²-9+9/(x-3)²)*(x/3-3/x)²=4

Answer 1

1
9/(x+3)²+18/(x-3)(x+3)+9/(x-3)²=(9x²-54x+81+18x²-162+9x²+54x+81)/(x²-9)²=
=36x²/(x²-9)²
2)(x/3-3/x)²=(x²-9)²/9x²
3)36x²/(x²-9)² *(x²-9)²/9x²=4