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跪求8道数学题,7年级的分组分解法,明天要交的(哭.)

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/18 04:01:37
跪求8道数学题,7年级的分组分解法,明天要交的(哭.)
ab-ac+b-c; a²-ab-2a+2b; 3a-9b+2ac-6ac;
3x²y+6xy-4x-8; x²+3y-xy-3x; x³+2xy-9x-18y;
(y+2)x²+(y+2)x-12y-24; m²x²+n²y²-m²y²-n²x²;
ab-ac+b-c;
  = (ab-ac)+(b-c)
  =a(b-c)+
(b-c)
  = (b-c)
(a+1)
  a²-ab-2a+2b;
  =(a²-ab-()2a-2b)
  =a(a-b)-2(a-b)
  =(a-b)(a-2)
  3a-9b+2ac-6ac;
  =好像有问题
3x²y+6xy-4x-8;
  =(3x²y+6xy)-(4x+8)
  =3xy(x+2)-4(x+2)
  =(x+2)(3xy-4)
  x²+3y-xy-3x;
  =(x²-xy)-(3x-3y)
  =x(x-y)-3(x-y)
  =(x-y)(x-3)
  x³+2xy-9x-18y;
  =(x²+2xy)-(9x+18y)
  =x(x+2y)-9(x+2y)
  =(x+2y)(x-9)
(y+2)x²+(y+2)x-12y-24;
  =(y+2)x²+(y+2)x-(12y+24)
  =(y+2)x²+(y+2)x-12(y+2)
  =(y+2)(x²+x-12)
  =(y+2)(x-3)(x+4)
  m²x²+n²y²-m²y²-n²x²
  =(m²x²-n²x²)-(m²y²-n²y²)
  =x²(m²-n²)-y²(m²-n²)
  =(m²-n²)(x²-y²)
  =(m-n)(m+n)(x-y)(x+y)