X^6+x^4 _______ x^4+x^2 x^6-x^8 _______ x^4-x^2
(х^4 (х^2 +1))/( х^2 (х^2 +1))=х^2 (х^6 (1-х^2))/(х^2 (х^2-1))=-х^4
1) [x⁴(x²+1)]/(x²(x²+1))=x⁴/x²=x² 2) [-x⁶(x²-1)]/(x²(x²-1))= -x⁶/x²= -x⁴