Question

求这三题答案

求这三题答案初二数学

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Answer 1

12/(m^2-9)-2/(m-3)=12/[(m+3)(m-3)]-2(m+3)/[(m-3)(m+3)]=(12-2m-6)/[(m+3)(m-3)]=-2(m+3)/[(m+3)(m-3)]=-2/(m-3)

追答

9/(x^-9)+3/(x+3)-1/(x-3))

9/(x^-9)+3/(x+3)-1/(x-3)=(9+3x-9-x-3)/(x-3)(x+3)=3(x-1)/(x-3)(x+3)

追问

能不能写在纸上

追答

Answer 2

1) =12/(m+3)(m-3) - 2(m+3)/(m+3)(m-3)
=12/(m+3)(m-3) - 2(m+3)/m^2-9
=12-2m-6/(m+3)(m-3)
=2(3-m)/(m+3)(m-3)
=-2/(m+3)

2) =9/(x+3)(x-3) + 3(x-3)/(x+3)(x-3) - (x+3)/(x+3)(x-3)
=(9+3x-9-x-3)/(x+3)(x-3)
=(2x-3)/(x^2-9)

3)右边看不清