x^2n+6x^n-y^2m+9因式分解

x^2n+6x^n-y^2m+9因式分解


x^2n+6x^n-y^2m+9
=(x^2n+6x^n+9)-y^2m
=(x^n+3)^2-y^2m
=(x^n+3+y^m)(x^n+3-y^m)