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计算(7/x^2+x)-(1/x^2-x)+(6/1-x^2)哪个是对的啊
题目详情
计算(7/x^2+x)-(1/x^2-x)+(6/1-x^2)
哪个是对的啊
哪个是对的啊
▼优质解答
答案和解析
解7/(x^2+x)-1/(x^2-x)+6/(1-x^2)
=7/x(x+1)-1/x(x-1)-6/(x+1)(x-1)
=7(x-1)/x(x+1)(x-1)-(x+1)/x(x+1)(x-1)-6x/x(x+1)(x-1)
=(7x-7-x-1-6x)/x(x+1)(x-1)
=-8/(x^3-x)
=7/x(x+1)-1/x(x-1)-6/(x+1)(x-1)
=7(x-1)/x(x+1)(x-1)-(x+1)/x(x+1)(x-1)-6x/x(x+1)(x-1)
=(7x-7-x-1-6x)/x(x+1)(x-1)
=-8/(x^3-x)
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