1 x^2-y^2+2x-4y-32 x^4+x^2-2ax-a^2+13 a^3+b^3+3(a^2+b^2)+3(a+b)+24 3x^2+5xy-2y^2+x+9y-4都是因式分解

1 x^2-y^2+2x-4y-3
2 x^4+x^2-2ax-a^2+1
3 a^3+b^3+3(a^2+b^2)+3(a+b)+2
4 3x^2+5xy-2y^2+x+9y-4
都是因式分解

1、=(x^2+2x+1)-(y^2+4y+4)=(x+1)^2-(y+2)^2
=(x+1-y-2)(x+1+y+2)=(x-y-1)(x+y+3)
2、=(x^4+2x^2+1)-(x^2+2ax-a^2)=(x^2+1)^2-(x-a)^2
=(x^2+1-x+a)(x^2+1+x-a)

1.(x+1)的平方-(y+2)的平方

1.
x^2-y^2+2x-4y-3
=(x^2+2x+1)-(y^2+4y+4)
=(x-1)^2-(y-2)^2
=(x-y+1)(x+y-3)
2.
x^4+x^2-2ax-a^2+1
=x^4+(x-a)^2+1
3.
a^3+b^3+3(a^2+b^2)+3(a+b)+2
=(a+b)^3-3a^b-3...

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1.
x^2-y^2+2x-4y-3
=(x^2+2x+1)-(y^2+4y+4)
=(x-1)^2-(y-2)^2
=(x-y+1)(x+y-3)
2.
x^4+x^2-2ax-a^2+1
=x^4+(x-a)^2+1
3.
a^3+b^3+3(a^2+b^2)+3(a+b)+2
=(a+b)^3-3a^b-3ab^2+3(a+b)^2-6ab+3(a+b)+2
=(a+b)^3-3ab(a+b)+3(a+b)^2-6ab+3(a+b)+2
=(a+b)^3+2(a+b)^2+(a+b)-3ab(a+b)+(a+b)^2-6ab+2(a+b)+2
=(a+b)(a+b+1)^2-3ab(a+b+2)+(a+b)^2+2(a+b)+1+1
=(a+b)(a+b+1)^2-3ab(a+b+2)+(a+b+1)^2+1
=(a+b+1)^2(a+b+1)-3ab(a+b+2)+1
=(a+b+1)^3-3ab(a+b+2)+1
4.
3x^2+5xy-2y^2+x+9y-4
=(3x-y)(x+2y)+x+9y-4

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