3x-12x^3x^2(x-y)+(y-x)-a^4-49b^2+14a^2ba^2(m-n)+b^2(n-m)16(a-1)^2-(a+2)^2ax^2+2ax-8a

3x-12x^3x^2(x-y)+(y-x)-a^4-49b^2+14a^2ba^2(m-n)+b^2(n-m)16(a-1)^2-(a+2)^2ax^2+2ax-8a
3x-12x^3
x^2(x-y)+(y-x)
-a^4-49b^2+14a^2b
a^2(m-n)+b^2(n-m)
16(a-1)^2-(a+2)^2
ax^2+2ax-8a

3x-12x^3x^2(x-y)+(y-x)-a^4-49b^2+14a^2ba^2(m-n)+b^2(n-m)16(a-1)^2-(a+2)^2ax^2+2ax-8a
3x-12x^3
=3x(1-4x^2)
=3x(1+2x)(1-2x)
x^2(x-y)+(y-x)
=(x-y)(x^2-1)
=(x-y)(x+1)(x-1)
-a^4-49b^2+14a^2b
=-(a^4-14a^2b+49b^2)
=-(a^2-7b)^2
a^2(m-n)+b^2(n-m)
=(m-n)(a^2-b^2)
=(m-n)(a+b)(a-b)
16(a-1)^2-(a+2)^2
=[4(a-1)]^2-(a+2)^2
=(4a-4+a+2)(4a-4-a-2)
=(5a-2)(3a-6)
ax^2+2ax-8a
=a(x^2+2x-8)
=a(x+4)(x-2)

打数字真是纠结的一件事：
3x-12x^3 = 3x(1 -4x^2) = 3x(1-2x)(1+2x)
x^2(x-y)+(y-x) = (x-y)(x+1)(x-1)
-a^4-49b^2+14a^2b = -(a^4 -14a^2*b + (7b)^2)= -(a^2-7b)^2
a^2(m-n)+b^2(n-m) = （m-n）(a^2-b^2)=(m-n)...

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打数字真是纠结的一件事：
3x-12x^3 = 3x(1 -4x^2) = 3x(1-2x)(1+2x)
x^2(x-y)+(y-x) = (x-y)(x+1)(x-1)
-a^4-49b^2+14a^2b = -(a^4 -14a^2*b + (7b)^2)= -(a^2-7b)^2
a^2(m-n)+b^2(n-m) = （m-n）(a^2-b^2)=(m-n)(a+b)(a-b)
16(a-1)^2-(a+2)^2 = (4a-4)^2 -(a+2)^2 = 3(5a-2)(a-2)
ax^2+2ax-8a = ax^2 +2ax+a-9a = a(x+1)^2 -9a =a(x-2)(x+4)

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3x(1-4x^2)=3x(1-2x)(1+2x)
x^2(x-y)+(y-x)=(x-y)(x^2-1)=(x-y)(x-1)(x+1)
-a^4-(7b)^2+2*7ab=-(a^2-7b)^2
a^2(m-n)+b^2(n-m)
=(m-n)(a^2-b^2)=(m-n)(a-b)(a+b)
16(a-1)^2-(a+2)^2=(4a-4-a-2)(4a-4+a+2)
=(3a-6)(5a-2)=3(a-2)(5a-2)
ax^2+2ax-8a=a(x^2+2x-8)
=a(x+4)(x-2)

3x(1-2x)(1+2x)
(x-y)(x-1)(x+1)
(a^2-7b)(7b-a^2)
(m-n)(a-b)(a+b)
(4a-4-a-2)(4a-4+a+2)=(3a-6)(5a-2)
(x-2a)(ax+4a)

3x-12x^3=3x(1-4x^2)=3x(1-2x)(1+2x)
x^2(x-y)+(y-x)=(x^2-1)(x-y)=(x-1)(x+1)(x-y)
-a^4-49b^2+14a^2b=-(a^4-14a^2b+49b^2)=-(a^2-7b)^2
a^2(m-n)+b^2(n-m)=(a^2-b^2)(m-n)=(a-b)(a+b)(m-n)
16(a-1)^2-(a+2)^2=[4(a-1)-(a+2)][4(a-1)+(a+2)]=(3a-6)(5a-2)
ax^2+2ax-8a=a(x^2+2x-8)a(x+4)(x-2)
一样的不准发？

3x-12x^3
=3x(1-4x^2)=3x(1-2x)(1+2x)
x^2(x-y)+(y-x)
=(x-y)(x^2-1)=(x-y)(x-1)(x+1)
-a^4-49b^2+14a^2b
=-(a^4+49b^2-14a^2b)=-(a^2-7b)^2
a^2(m-n)+b^2(n-m)
=(m-n)(a^2-b^2)=(m-n)(...

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3x-12x^3
=3x(1-4x^2)=3x(1-2x)(1+2x)
x^2(x-y)+(y-x)
=(x-y)(x^2-1)=(x-y)(x-1)(x+1)
-a^4-49b^2+14a^2b
=-(a^4+49b^2-14a^2b)=-(a^2-7b)^2
a^2(m-n)+b^2(n-m)
=(m-n)(a^2-b^2)=(m-n)(a+b)(a-b)
16(a-1)^2-(a+2)^2
=[4(a-1)]^2-(a+2)^2=(5a-2)(3a-6)=3(5a-2)(a-2)
ax^2+2ax-8a
=a(x^2+2x+1-9)=a[(x+1)^2-9]=a(x+4)(x-2)

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