x^4-1-4x^2-4x
=x⁴-(1+4x²+4x)
=x⁴-(1+2x)²
=(x²-1-2x)(x²+1+2x)
=(x²-2x-1)(x+1)²你怎么才来刚才在吃饭又在吃饭我每天7点左右吃饭