① 4(x-3)平方—(2x+1)平方=(3x+1)(1—3x)+9x平方 (解方程)②-2m六次+6m四次+8m两次(分解因式)③(x平方—5x)(x平方—5x—10)—56 (分解因式)④(a+1)(a+2)(a+3)(a+4)—3
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![① 4(x-3)平方—(2x+1)平方=(3x+1)(1—3x)+9x平方 (解方程)②-2m六次+6m四次+8m两次(分解因式)③(x平方—5x)(x平方—5x—10)—56 (分解因式)④(a+1)(a+2)(a+3)(a+4)—3](/uploads/image/z/7099651-19-1.jpg?t=%E2%91%A0+4%EF%BC%88x-3%EF%BC%89%E5%B9%B3%E6%96%B9%E2%80%94%EF%BC%882x%2B1%EF%BC%89%E5%B9%B3%E6%96%B9%3D%EF%BC%883x%2B1%EF%BC%89%EF%BC%881%E2%80%943x%EF%BC%89%2B9x%E5%B9%B3%E6%96%B9+%EF%BC%88%E8%A7%A3%E6%96%B9%E7%A8%8B%EF%BC%89%E2%91%A1-2m%E5%85%AD%E6%AC%A1%2B6m%E5%9B%9B%E6%AC%A1%2B8m%E4%B8%A4%E6%AC%A1%EF%BC%88%E5%88%86%E8%A7%A3%E5%9B%A0%E5%BC%8F%EF%BC%89%E2%91%A2%EF%BC%88x%E5%B9%B3%E6%96%B9%E2%80%945x%EF%BC%89%EF%BC%88x%E5%B9%B3%E6%96%B9%E2%80%945x%E2%80%9410%EF%BC%89%E2%80%9456+%EF%BC%88%E5%88%86%E8%A7%A3%E5%9B%A0%E5%BC%8F%EF%BC%89%E2%91%A3%EF%BC%88a%2B1%EF%BC%89%EF%BC%88a%2B2%EF%BC%89%EF%BC%88a%2B3%EF%BC%89%EF%BC%88a%EF%BC%8B4%EF%BC%89%E2%80%943)
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① 4(x-3)平方—(2x+1)平方=(3x+1)(1—3x)+9x平方 (解方程)②-2m六次+6m四次+8m两次(分解因式)③(x平方—5x)(x平方—5x—10)—56 (分解因式)④(a+1)(a+2)(a+3)(a+4)—3
① 4(x-3)平方—(2x+1)平方=(3x+1)(1—3x)+9x平方 (解方程)
②-2m六次+6m四次+8m两次(分解因式)
③(x平方—5x)(x平方—5x—10)—56 (分解因式)
④(a+1)(a+2)(a+3)(a+4)—3(分解因式)
⑤已知xy+x—y+1=6,(1—x平方)(1—y平方)+4xy=48,求xy—x+y+1的值
① 4(x-3)平方—(2x+1)平方=(3x+1)(1—3x)+9x平方 (解方程)②-2m六次+6m四次+8m两次(分解因式)③(x平方—5x)(x平方—5x—10)—56 (分解因式)④(a+1)(a+2)(a+3)(a+4)—3
① 4(x-3)平方—(2x+1)平方=(3x+1)(1—3x)+9x平方 (解方程)
(2(x-3)+(2x+1))(2(x-3)-(2x+1))=(1+3x)(1—3x)+9x平方
(4x-5)(-7)=1-9x^2+9x^2
-28x+35=1
28x=34
x=17/14
②-2m六次+6m四次+8m两次(分解因式)
=-2m^2(m^4-3m^2-4)
=-2m^2(m^2-4)(m^2+1)
=-2m^2(m-2)(m+2)(m^2+1)
③(x平方—5x)(x平方—5x—10)—56 (分解因式)
=(x^2-5x)^2-10(x^2-5x)-56
=(x^2-5x-14)(x^2-5x+4)
=(x-7)(x+2)(x-1)(x-4)
④(a+1)(a+2)(a+3)(a+4)—3(分解因式)
=(a+1)(a+4)(a+2)(a+3)—3
=(a^2+5a+4)(a^2+5a+6)-3
=(a^2+5a+4)(a^2+5a+4+2)-3
=(a^2+5a+4)^2+2(a^2+5a+4)-3
=(a^2+5a+4-1)(a^2+5a+4+3)
=(a^2+5a+3)(a^2+5a+7)
⑤已知xy+x—y+1=6,
(1—x平方)(1—y平方)+4xy=48,
(1-x^2)(1-y^2)+4xy=48
1-y^2-x^2+x^2*y^2+4xy=48
2xy-y^2-x^2+(1+xy)^2=48
-(x-y)^2+(1+xy)^2=48
(xy+1)^2-(x-y)^2=48
(xy+1+x-y)(xy+1-x+y)=48
因为xy+x—y+1=6,
所以xy-x+y+1=8