已知x+y/xy=4
xy/(x+y)=1/4
代数式5xy/4x+4y 减2x+2y/6xy的值
=5/4(xy/x+y) -1/3(x+y/xy)
=5/4*1/4 -1/3*4
=5/16 -4/3
=-49/48做对了 可以说下思路吗代数式5xy/4x+4y 减2x+2y/6xy的值（提取公因数）=5xy/4(x+y) -(x+y)/3xy =5/4(xy/x+y) -1/3(x+y/xy)=5/4*1/4 -1/3*4=5/16 -4/3=-49/48