计算：x^2-y^2/x^2-9y^2+(x-2y)^2/9y^2-x^2+5y^2-4xy/x^2-9y^2_数学解答

计算：x^2-y^2/x^2-9y^2+(x-2y)^2/9y^2-x^2+5y^2-4xy/x^2-9y^2

人气：127 ℃　时间：2020-02-03 02:14:08

解答

原式=(x²-y²)/(x²-9y²)-(x²-4xy+4y²)/(x²-9y²)+(5y²-4xy)/(x²-9y²)=(x²-y²-x²+4xy-4y²+5y²-4xy)/(x²-9y²)=0/(x²-...