化简:[1+N/M -M/(M-N)]÷[(1-N/M -M/(M+N)] ,

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化简:[1+N/M-M/(M-N)]÷[(1-N/M-M/(M+N)] ,化简:[1+N/M-M/(M-N)]÷[(1-N/M-M/(M+N)] ,化简:[1+N/M-M/(M-N)]÷[(1-N/M

化简:[1+N/M -M/(M-N)]÷[(1-N/M -M/(M+N)] ,
化简:[1+N/M -M/(M-N)]÷[(1-N/M -M/(M+N)] ,

化简:[1+N/M -M/(M-N)]÷[(1-N/M -M/(M+N)] ,
原式=[(m+n)/m - m/(m-n)]÷[(m-n)/m -m/(m+n)]
=[(m+n)(m-n)-m²]/m(m-n) ÷ [(m+n)(m-n)-m²]/m(m+n)
= (m²-n²-m²)/m(m-n) × m(m+n)/(m²-n²-m²)
=(m+n)/(m-n)

设原式为y,则:
y=[(m-n)/(m-n)+n/m-m/(m-n)]/[(m+n)/(m+n)-n/m-m/(m+n)]
=[n/m-n/(m-n)]/[n/(m+n)-n/m]
=[1/m-1/(m-n)]/[1/(m+n)-1/m]
={-n/[m(m-n)]}/{-n/[m(m+n)]}
=[1/(m-n)]/[1/(m+n)]
=(m+n)/(m-n)

设原式为y,则 y=[(m+n)/m - m/(m-n)]÷[(m-n)/m -m/(m+n)]
=[(m+n)(m-n)-m²]/m(m-n) ÷ [(m+n)(m-n)-m²]/m(m+n)
= (m²-n²-m²)/m(m-n) × m(m+n)/(m²-n²-m²)
=(m+n)/(m-n) 注:1=m/m,代入原式就能算出了。