分解因式:1,a³ +27 2,8-m³ 3,-27x³+8 4,y²(x
1个回答

1,a³ +27

=(a+3)(a²-3a+9)

2,8-m³

=(2-m)(4+2m+m²)

3,-27x³+8

=-(3x-2)(9x²+6x+4)

4,y²(x²-2x)³﹢y²

=y²[(x²-2x)³+1]

=y²(x²-2x+1)(x^4-4x³+4x²+x²-2x+1)

=y²(x-1)²(x^4-4x³+5x²-2x+1)

5,4xy+1-4x²-y²

=1-(4x²-4xy+y²)

=1-(2x-y)²

=(1+2x-y)(1-2x+y)

6,a⁴b+a³b²-a²b²-ab⁴

建议改成a⁴b+a³b²-a²b³-ab⁴

=ab(a³+a²b-ab²-b³)

=ab(a+b)(a²-b²)

=ab(a+b)²(a-b)