1.3^(2m) + 3^(m+2) + 81/4=(3^m)^2+(3^m)*9+9/2)^2=(3^m+9/2)^2
2.x^(2n) + 6x^n - y^2 +9 =(x^n)^2+6x^n+9-y^2=(x^n+3)^2-y^2=(x^n+3+3)(x^n+3-3)=(x^n)(x^n+6)