计算:(m-1/m^2+3m+2)-(6/m^2-m-2)通分:x-2/4x^2-4x,x-1/x^2-2x,1/x^3-3x^2+2x

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计算:(m-1/m^2+3m+2)-(6/m^2-m-2)
通分:x-2/4x^2-4x,x-1/x^2-2x,1/x^3-3x^2+2x

(m-1)/(m^2+3m+2)-6/(m^2-m-2)
=(m-1)/(m+1)(m+2)-6/(m+1)(m-2)
=(m-1)(m-2)/(m+1)(m+2)(m-2) -6(m+2)/(m+1)(m+2)(m-2)
=(m^2-3m+2-6m-12)/(m+1)(m+2)(m-2)
=(m^2-9m-10)/(m+1)(m+2)(m-2)
=(m+1)(m-10)/(m+1)(m+2)(m-2)
=(m-10)/(m+2)(m-2)
=(m-10)/(m^2-4)

1、原式=(m-1)/(m+1)(m+2)-6/(m-2)(m+1)=[(m-1)(m-2)-6(m+2)]/(m+2)(m-2)(m+1)=[(m^2-3m+2)-6m-12]/(m+2)(m-2)(m+1)=(m^2-9m-10)/(m+2)(m-2)(m+1)=(m-10)(m+1)/(m+2)(m-2)(m+1)=(m-10)/(m+2)(m-2)
2、公分母为4x(x-1)(x-2)