紧急求教初二数学题！（根据答题多少追加悬赏分）

来源：百度知道 编辑：UC知道 时间：2024/06/15 08:35:35
把下列各式分解因式：

1) a^4-7a^2-18

2)xy(x-y)+yz(y-z)+zx(z-x)

3)(x^2-6x+4)(x^2-6x+6)-8

4)x^2-y^2-x+2y-3/4

5)x^2-(a+1/a)x+1

6)a^2+(15/4)a-1

为了防止“血本无归”的事情发生，因此才把悬赏分设低，不过如果你解答得多，我会追加悬赏分的！拜托了~

1. (a^2-9)(a^2+2)
3. (x^2-6x)^2 + 10(x^2-6x) +24-8
= (x^2-6x+2)(x^2-6x+8)
4. =(x^2-x+¼) -(y^2 -2y+1)
= (x-1/2)^2 -(y-1)^2
5. = (x-a)(x-1/a)
6. =(¼)(4a^2+15a-4)
= (¼)(a+4)(4a-1)
2. = yx^2-xy^2+zy^2-yz^2+xz^2-zx^2
= x^2(y-z)+x(z^2-y^2)+(zy^2-yz^2)
= (y-z)[x^2-x(y+z)+yz]
= (y-z)(x-y)(x-z)

1. (a^2-9)(a^2+2)
3. (x^2-6x)^2 + 10(x^2-6x) +24-8
= (x^2-6x+2)(x^2-6x+8)
4. =(x^2-x+1/4) -(y^2 -2y+1)
= (x-1/2)^2 -(y-1)^2
5. = (x-a)(x-1/a)
6. =(1/4)(4a^2+15a-4)
= (1/4)(a+4)(4a-1)
2. = yx^2-xy^2+zy^2-yz^2+xz^2-zx^2
= x^2(y-z)+x(z^2-y^2)+(zy^2-yz^2)
= (y-z)[x^2-x(y+z)+yz]
= (y-z)(x-y)(x-z)
楼下的悠然依水，抄袭很可耻

1)
a^4 - 7a^2 - 18 ............. a^2
= (a^2)^2 - 7(a^2) - 18
= (a^2 + 2)(a^2 - 9)
= (a - 3)(a + 3)(a^2 + 2)

2)
xy(x-y) + yz(y-z) + zx(z-x)

3)
(x^2-6x+4)(x^2-6x+6)-8 ..