10道因式分解1.-7m(m-n)^3+21mn(n-m)^22.5x(x-2y)^2-10y(2y-x)^23.225(x-y)^2-196(x+y)^24.(5x-3y)^2-(3x-5y)^25.(5m^2+8n^2)^2-(4m^2+n^2)^26.x^3+x^2y-xy^2-y^37.9m^2-15m+4分之258.(a^2-1)^2+6(1-a^2)+99.a^2-9b^2+6b-110.mn^2-2mn+2n-4
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![10道因式分解1.-7m(m-n)^3+21mn(n-m)^22.5x(x-2y)^2-10y(2y-x)^23.225(x-y)^2-196(x+y)^24.(5x-3y)^2-(3x-5y)^25.(5m^2+8n^2)^2-(4m^2+n^2)^26.x^3+x^2y-xy^2-y^37.9m^2-15m+4分之258.(a^2-1)^2+6(1-a^2)+99.a^2-9b^2+6b-110.mn^2-2mn+2n-4](/uploads/image/z/1239421-13-1.jpg?t=10%E9%81%93%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A31.-7m%28m-n%29%5E3%2B21mn%28n-m%29%5E22.5x%28x-2y%29%5E2-10y%282y-x%29%5E23.225%28x-y%29%5E2-196%28x%2By%29%5E24.%285x-3y%29%5E2-%283x-5y%29%5E25.%285m%5E2%2B8n%5E2%29%5E2-%284m%5E2%2Bn%5E2%29%5E26.x%5E3%2Bx%5E2y-xy%5E2-y%5E37.9m%5E2-15m%2B4%E5%88%86%E4%B9%8B258.%28a%5E2-1%29%5E2%2B6%281-a%5E2%29%2B99.a%5E2-9b%5E2%2B6b-110.mn%5E2-2mn%2B2n-4)
10道因式分解1.-7m(m-n)^3+21mn(n-m)^22.5x(x-2y)^2-10y(2y-x)^23.225(x-y)^2-196(x+y)^24.(5x-3y)^2-(3x-5y)^25.(5m^2+8n^2)^2-(4m^2+n^2)^26.x^3+x^2y-xy^2-y^37.9m^2-15m+4分之258.(a^2-1)^2+6(1-a^2)+99.a^2-9b^2+6b-110.mn^2-2mn+2n-4
10道因式分解
1.-7m(m-n)^3+21mn(n-m)^2
2.5x(x-2y)^2-10y(2y-x)^2
3.225(x-y)^2-196(x+y)^2
4.(5x-3y)^2-(3x-5y)^2
5.(5m^2+8n^2)^2-(4m^2+n^2)^2
6.x^3+x^2y-xy^2-y^3
7.9m^2-15m+4分之25
8.(a^2-1)^2+6(1-a^2)+9
9.a^2-9b^2+6b-1
10.mn^2-2mn+2n-4
10道因式分解1.-7m(m-n)^3+21mn(n-m)^22.5x(x-2y)^2-10y(2y-x)^23.225(x-y)^2-196(x+y)^24.(5x-3y)^2-(3x-5y)^25.(5m^2+8n^2)^2-(4m^2+n^2)^26.x^3+x^2y-xy^2-y^37.9m^2-15m+4分之258.(a^2-1)^2+6(1-a^2)+99.a^2-9b^2+6b-110.mn^2-2mn+2n-4
1.-7m(m-n)^3+21mn(n-m)^2
=-7m(m-n)^3+21mn(m-n)^2
=-7m(m-n)^2[(m-n)-3n]
=-7m(m-n)^2(m-4n)
2.5x(x-2y)^2-10y(2y-x)^2
=5x(x-2y)^2-10y(x-2y)^2
=5(x-2y)^3(x-2y)
3.225(x-y)^2-196(x+y)^2
=[15(x-y)]²-[14(x+y)^2
=[15(x-y)+14(x+y)][15(x-y)-14(x+y)]
=(15x-15y+14x+14y)(15x-15y-14x-14y)
=(29x-y)(x-29y)
4.(5x-3y)^2-(3x-5y)^2
=[(5x-3y)+(3x-5y)][(5x-3y)-(3x-5y)]
=(8x-8y)(2x+2y)
=16(x-y)(x+y)
5.(5m^2+8n^2)^2-(4m^2+n^2)^2
=(5m^2+8n^2+4m^2+n^2)(5m^2+8n^2-4m^2-4n^2)
=(9m^2+9n^2)(m^2+4n^2)
=9(m^2+n^2)(m^2+4n^2)
6.x^3+x^2y-xy^2-y^3
=(x^3+x^2y)-(xy^2+y^3)
=x^2(x+y)-y^2(x+y)
=(x+y)(x^2-y^2)
=(x+y)(x+y)(x-y)
=(x-y)(x+y)^2
7.9m^2-15m+4分之25
=(3m)^2-15m+(5/2)^2
=(3m-5/2)^2
8.(a^2-1)^2+6(1-a^2)+9
=(a^2-1)^2-6(a^2-1)+9
=(a^2-1-3)^2
=(a^2-4)^2
=(a+2)^2(a-2)^2
9.a^2-9b^2+6b-1
=a^2-(9b^2-6b+1)
=a^2-(3b-1)^2
=(a+3b-1)(a-3b+1)
10.mn^2-2mn+2n-4
=(mn^2-2mn)+(2n-4)
=mn(n-2)+2(n-2)
=(n-2)(mn+2)
1.-7m(m-n)^3+21mn(n-m)^2
=7m(n-m)^2(3n+m) (提取公因式)
2.5x(x-2y)^2-10y(2y-x)^2
=5(x-2y)^2(X-2Y)=5(x-2y)^3 (提取公因式)
3.225(x-y)^2-196(x+y)^2
=[15(X-Y)-14(X+Y)][15(X-Y)+14(X+Y)]
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1.-7m(m-n)^3+21mn(n-m)^2
=7m(n-m)^2(3n+m) (提取公因式)
2.5x(x-2y)^2-10y(2y-x)^2
=5(x-2y)^2(X-2Y)=5(x-2y)^3 (提取公因式)
3.225(x-y)^2-196(x+y)^2
=[15(X-Y)-14(X+Y)][15(X-Y)+14(X+Y)]
=(X-29Y)(29X+Y) A²-B²=(A+B)(A-B)
4.(5x-3y)^2-(3x-5y)^2
=(5x-3y+3x-5y)(5x-3y-3x+5y)=(8x-8y)(2x+2y)=16(x-y)(x+y)
A²-B²=(A+B)(A-B)
5.(5m^2+8n^2)^2-(4m^2+n^2)^2 用公式:A²-B²=(A+B)(A-B)
6.x^3+x^2y-xy^2-y^3=x^3-y^3+x^2y-xy^2
=(x-y)(x^2+xy+y^2)+xy(x-y)=(x-y)(x^2+xy+y^2+xy)
=(x-y)(x+y)^2
7.9m^2-15m+4分之25
=9(m^2-5/3m+25/36)+25/4-25/4=9(m-5/6)^2 ( 配方)
=(3m-5/2)^2
8.(a^2-1)^2+6(1-a^2)+9
=(a^2-1)^2-6(a^2-1)+9=(a^2-1+3)^2=(a^2+2)^2
9.a^2-9b^2+6b-1
=a^2-(9b^2-6b+1)=a^2-(3b-1)^2=(a+3b-1)(a-3b+1) (分组分解)
10.mn^2-2mn+2n-4
=(mn^2-2mn)+(2n-4)=mn(n-2)+2(n-2)
=(n-2)(mn+2) (分组分解)
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