紧急求教初二数学题！（根据答题多少追加悬赏分）

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 ............. x^2 - 6x + 5
= (x^2 - 6x + 5)^2 - 1 - 8
= (x^2 - 6 x + 2)(x^2 - 6x + 8)

4)
x^2 - y^2 - x + 2y - 3/4
= (x^2 - x) - (y^2 - 2y) - 3/4
= [(x - 1/2)^2 - 1/4] - [(y - 1)^2 - 1] -4/3
= (x - 1/2)^2 - (y - 1)^2
= (x - y + 1/2)(x + y - 3/2)

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

6)
a^2 + (15/4)a - 1
= a^2 + 2*(15/8)a + (15/8)^2 - (15/8)^2 - 1
= (a + 15/8)^2 - (17/8)^2
= (a - 2/8)(a + 514/64)
= (a - 1/4)(a + 257/32)