因式分解 1,x^4-7x^2-24x-15 2,-2x^+5xy+2y^2 3,x^3+2xy-x-xy^2 4,x^
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因式分解 1,x^4-7x^2-24x-15 2,-2x^+5xy+2y^2 3,x^3+2xy-x-xy^2 4,x^-2x-4 5,4x^+8x-1
6 ,-x方-y方+2xy+1
6 ,-x方-y方+2xy+1
![因式分解 1,x^4-7x^2-24x-15 2,-2x^+5xy+2y^2 3,x^3+2xy-x-xy^2 4,x^](/uploads/image/z/17074454-14-4.jpg?t=%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3+1%2Cx%5E4-7x%5E2-24x-15+2%2C-2x%5E%2B5xy%2B2y%5E2+3%2Cx%5E3%2B2xy-x-xy%5E2+4%2Cx%5E)
1:x^4-7x^2-24x-15=(x^2-3x-3)(x^2+3x+5)
2:-2x^2+5xy+2y^2 =2(y+x)(y-x)+5xy
3:x³+2xy-x-xy²
=x(x²+2y-1-y²)
=x[x²-(y²-2y+1)]
=x[x²-(y-1)²]
=x[x-(y-1)][x+(y-1)]
=x(x-y+1)(x+y-1)
4:x^2-2x-4=(X-1)^2-5=(X-1-根5)(X-1+根5)
5:4x^2+8x-1
=4(x+1)^2-5
=(2x+2)^2-(根号5)^2
=(2x+2+根号5)(2x+2-根号5)
6:-x^2-y^2+2xy+1=-(x-y)^2+1=(1+x-y)(1-x+y)
2:-2x^2+5xy+2y^2 =2(y+x)(y-x)+5xy
3:x³+2xy-x-xy²
=x(x²+2y-1-y²)
=x[x²-(y²-2y+1)]
=x[x²-(y-1)²]
=x[x-(y-1)][x+(y-1)]
=x(x-y+1)(x+y-1)
4:x^2-2x-4=(X-1)^2-5=(X-1-根5)(X-1+根5)
5:4x^2+8x-1
=4(x+1)^2-5
=(2x+2)^2-(根号5)^2
=(2x+2+根号5)(2x+2-根号5)
6:-x^2-y^2+2xy+1=-(x-y)^2+1=(1+x-y)(1-x+y)