已知m\n=5\3,求(m\m+n)+(m\m-n)-(n@\m@-n@)的值,@代表平方.
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![已知m\n=5\3,求(m\m+n)+(m\m-n)-(n@\m@-n@)的值,@代表平方.](/uploads/image/z/601705-1-5.jpg?t=%E5%B7%B2%E7%9F%A5m%5Cn%3D5%5C3%2C%E6%B1%82%EF%BC%88m%5Cm%2Bn%EF%BC%89%2B%EF%BC%88m%5Cm-n%EF%BC%89-%28n%EF%BC%A0%5Cm%EF%BC%A0-n%EF%BC%A0%EF%BC%89%E7%9A%84%E5%80%BC%2C%EF%BC%A0%E4%BB%A3%E8%A1%A8%E5%B9%B3%E6%96%B9.)
已知m\n=5\3,求(m\m+n)+(m\m-n)-(n@\m@-n@)的值,@代表平方.
已知m\n=5\3,求(m\m+n)+(m\m-n)-(n@\m@-n@)的值,@代表平方.
已知m\n=5\3,求(m\m+n)+(m\m-n)-(n@\m@-n@)的值,@代表平方.
(m\m+n)+(m\m-n)-(n@\m@-n@)
=m(m-n)/(m+n)(m-n)+m(m+n)/(m+n)(m-n)-n^2/(m+n)(m-n)
=(m^2-mn+m^2+mn-n^2)/(m+n)(m-n)
=(2m^2-n^2)/(m^2-n^2)
m\n=5\3 so 3n=5m 设n=5k 那么 m=3k
(2m^2-n^2)/(m^2-n^2)
=(2*9k^2-25k^2)/(9k^2-25k^2)
=7/16
原式
=(m(m-n)+m(m+n)-n^2)/(m^2-n^2)
=(2m^2-n^2)/(m^2-n^2)
=(2(m/n)^2-1)/((m/n)^2-1)
=(2(25/9)-1)/((25/9)-1)
=41/16
m/n=5/3 得 m=5n/3
(m/m+n)+(m/m-n)-(n²/m²-n²)
=[m(m-n)+m(m+n)-n²]/(m²-n²)
=(m²-mn+m²+mn-n²)/(m²-n²)
=(2m²-n²)/(m&su...
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m/n=5/3 得 m=5n/3
(m/m+n)+(m/m-n)-(n²/m²-n²)
=[m(m-n)+m(m+n)-n²]/(m²-n²)
=(m²-mn+m²+mn-n²)/(m²-n²)
=(2m²-n²)/(m²-n²)
=[(2*25n²/9)-n²]/[25n²/9-n²]
=41n²/(16n²/9)
=939/16
应该是这样吧
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