题目

分解因式3m^2(x-y)^2+6m(y-x)^2; 2x^4+6x^2-8; x^3-3x^2-9x+27; 1-a^2-b^2+2ab

提问时间：2021-01-03

答案

=(3m²+6m)(x-y)²
=3m(m+2)(x-y)²
2x^4+6x^2-8
=2(x^4+3x²-4)
=2(x²+4)(x²-1)
=2(x²+4)(x+1)(x-1)
x^3-3x^2-9x+27
=x²(x-3)-9(x-3)
=(x²-9)(x-3)
=(x+3)(x-3)(x-3)
=(x+3)(x-3)²
1-a^2-b^2+2ab
=1-(a²-2ab+b²)
=1-(a-b)²
=(1+a-b)(1-a+b)