Объяснение:
(x²+2)²-4(x²+2)= (x²+2)(x²+2-4)=x²+2)(x²-2)
a²-x²-6x-9=a²-(x²+6x+9)=a²-(x+3)²=
=(a+(x+3))(a-(x+3))=(a+x+3)(a-x-3)
