①已知x=2009,y=2010,求代数式x-y/x÷(x-(2xy-y^2/x))的值②先化简,再求值:(a^2-b^2/a^2-ab)÷(a+(2ab+b^2/a)当b=-1时,再从-2<a<2的范围内选取一个合适的整数a代入求值大家帮帮忙啊~~~~~~~~急啊~~~~~~~
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![①已知x=2009,y=2010,求代数式x-y/x÷(x-(2xy-y^2/x))的值②先化简,再求值:(a^2-b^2/a^2-ab)÷(a+(2ab+b^2/a)当b=-1时,再从-2<a<2的范围内选取一个合适的整数a代入求值大家帮帮忙啊~~~~~~~~急啊~~~~~~~](/uploads/image/z/3011407-7-7.jpg?t=%E2%91%A0%E5%B7%B2%E7%9F%A5x%3D2009%2Cy%3D2010%2C%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8Fx-y%2Fx%C3%B7%EF%BC%88x-%EF%BC%882xy-y%5E2%2Fx%29%29%E7%9A%84%E5%80%BC%E2%91%A1%E5%85%88%E5%8C%96%E7%AE%80%2C%E5%86%8D%E6%B1%82%E5%80%BC%EF%BC%9A%EF%BC%88a%5E2-b%5E2%2Fa%5E2-ab%EF%BC%89%C3%B7%EF%BC%88a%2B%EF%BC%882ab%2Bb%5E2%2Fa%29%E5%BD%93b%3D-1%E6%97%B6%2C%E5%86%8D%E4%BB%8E-2%EF%BC%9Ca%EF%BC%9C2%E7%9A%84%E8%8C%83%E5%9B%B4%E5%86%85%E9%80%89%E5%8F%96%E4%B8%80%E4%B8%AA%E5%90%88%E9%80%82%E7%9A%84%E6%95%B4%E6%95%B0a%E4%BB%A3%E5%85%A5%E6%B1%82%E5%80%BC%E5%A4%A7%E5%AE%B6%E5%B8%AE%E5%B8%AE%E5%BF%99%E5%95%8A%7E%7E%7E%7E%7E%7E%7E%7E%E6%80%A5%E5%95%8A%7E%7E%7E%7E%7E%7E%7E)
①已知x=2009,y=2010,求代数式x-y/x÷(x-(2xy-y^2/x))的值②先化简,再求值:(a^2-b^2/a^2-ab)÷(a+(2ab+b^2/a)当b=-1时,再从-2<a<2的范围内选取一个合适的整数a代入求值大家帮帮忙啊~~~~~~~~急啊~~~~~~~
①已知x=2009,y=2010,求代数式x-y/x÷(x-(2xy-y^2/x))的值
②先化简,再求值:(a^2-b^2/a^2-ab)÷(a+(2ab+b^2/a)当b=-1时,再从-2<a<2的范围内选取一个合适的整数a代入求值
大家帮帮忙啊~~~~~~~~急啊~~~~~~~~~~~~
①已知x=2009,y=2010,求代数式x-y/x÷(x-(2xy-y^2/x))的值②先化简,再求值:(a^2-b^2/a^2-ab)÷(a+(2ab+b^2/a)当b=-1时,再从-2<a<2的范围内选取一个合适的整数a代入求值大家帮帮忙啊~~~~~~~~急啊~~~~~~~
本团长来帮你.
①已知x=2009,y=2010,求代数式x-y/x÷(x-(2xy-y^2/x))的值
(x-y)/x÷[x-(2xy-y^2/x)]
=(x-y)/x÷(x²-2x+y²)/x
=(x-y)/x÷(x-y)²/x
=1/(x-y)
=1/(2009-2010)
=-1
②先化简,再求值:(a^2-b^2/a^2-ab)÷(a+(2ab+b^2/a)当b=-1时,再从-2<a<2的范围内选取一个合适的整数a代入求值
(a²-b²)/(a²-ab)÷[a+(2ab+b²/a)]
=[(a-b)(a+b)/a(a-b)]÷(a²+2ab+b²)/a
=(a+b)/a÷(a+b)²/a
=1/(a+b) b=-1 设a=0
=1/(0-1)
=-1