а)(х^2-1)^2+6(x^2-1)+9=(X^2-1+3)^2=(x^2+2)^2
б)a^2-x^2+4x-4=a^2-(x^2-4x+4)=a^2-(x-2)^2=(a-x+2)(a+x-2)
а)(х^2-1)^2+6(x^2-1)+9=(X^2-1+3)^2=(x^2+2)^2
б)a^2-x^2+4x-4=a^2-(x^2-4x+4)=a^2-(x-2)^2=(a-x+2)(a+x-2)