分解公因式2a³-8ax⁴-16(a+b)²-4b²½x⁴y²-⅛x²y⁴9x²-16(a+b)²(x+y)³(x-y)-(x+y)(x-y)³25(x-2y)³+4（2y-x）81a的五次b的五次-ab要算式

Question

分解公因式
2a³-8a
x⁴-16
(a+b)²-4b²
½x⁴y²-⅛x²y⁴
9x²-16(a+b)²
(x+y)³(x-y)-(x+y)(x-y)³
25(x-2y)³+4（2y-x）
81a的五次b的五次-ab
要算式

Answer 1

漏了一个,补上：(x+y)³(x-y)-(x+y)(x-y)³=(x+y)(x-y)[(x+y)²-(x-y)²]
=(x+y)(x-y)(x+y+x-y)(x+y-x+y)
=4xy(x+y)(x-y)
（1）=2a(a²-4)=2a(a+2)(a-2)
（2）=(x²+4)(x²-4)=(x²+4)(x+2)(x-2)
（3）=(a+b+2b)(a+b-2b)=(a+3b)(a-b)
（4）=(1/8)x²y²(4x²-y²)=(1/8)x²y²(2x+y)(2x-y)
（5）=(3x+4a+4b)(3x-4a-4b)
（6）=(x-2y)[25(x-2y)²-4]=(x-2y)(5x-10y+2)(5x-10y-2)
（7）=ab(81a⁴b⁴-1)=ab(9a²b²+1)(9a²b²-1)=ab(9a²b²+1)(3ab+1)(3ab-1)