搜搜考试网(3x^2+9x+7)/(x+1)-(2x^2-4x+3)/(x-1)-(x^3+x+1)/(x^2-1)
来源：学生作业帮 编辑：搜搜考试网作业帮 分类：数学作业 时间：2024/05/06 11:58:09
(3x^2+9x+7)/(x+1)-(2x^2-4x+3)/(x-1)-(x^3+x+1)/(x^2-1)
不许通分,有更好的办法
只是第一步不许通分啊
不许通分,有更好的办法
只是第一步不许通分啊
(3x^2+9x+7)/(x+1)-(2x^2-4x+3)/(x-1)-(x^3+x+1)/(x^2-1)
=[3x(x+1)+6(x+1)+1)]/(x+1)-[2x(x-1)-2(x-1)+1])/(x-1)-[x(x^2-1)+(2x+1))/(x^2-1)
=3x+6+1/(x+1) - 2x+2-1/(x-1) - x- (2x+1)/(x^2-1)
=8+1/(x+1) -1/(x-1) -(2x+1)/(x^2-1)
=[8(x^2-1)+ (x-1)-(x+1)-(2x+1)]/(x^2-1)
=(8x^2-8+x-1-x-1-2x-1)/(x^2-1)
=(8x^2-2x-11)/(x^2-1)
=[3x(x+1)+6(x+1)+1)]/(x+1)-[2x(x-1)-2(x-1)+1])/(x-1)-[x(x^2-1)+(2x+1))/(x^2-1)
=3x+6+1/(x+1) - 2x+2-1/(x-1) - x- (2x+1)/(x^2-1)
=8+1/(x+1) -1/(x-1) -(2x+1)/(x^2-1)
=[8(x^2-1)+ (x-1)-(x+1)-(2x+1)]/(x^2-1)
=(8x^2-8+x-1-x-1-2x-1)/(x^2-1)
=(8x^2-2x-11)/(x^2-1)
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设函数f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10),
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1+x+x^2+x^3+.+x^99+x^100
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x+2/x^2-x-6 + 2x/x^3-3x - x+1/x^2-6x+9