3(x^2-1)^2+18(1-x^2)+27
问题描述：
3(x^2-1)^2+18(1-x^2)+27
3(x²-1)²+18（1-x²）+27
答
原式=3(x²-1)²-18(x²-1)+27
=3[(x²-1)²-6(x²-1)+9]
=3(x²-1-3)²
=3(x²-4)²
=3(x+2)²(x-2)²