x^2-y分之y(x-y)-x(x+y)除以x+y分之x^2+y^2.其中x=2,y=-1.先化简再求值.
问题描述：
x^2-y分之y(x-y)-x(x+y)除以x+y分之x^2+y^2.其中x=2,y=-1.先化简再求值.
答
=x^2-Y/-(Y^2+X^2)除以（X+Y）/X^2+Y^2
=(Y-X^2)/(X+Y)
= -5
答
x^2-(y(x-y)-x(x+y))/y÷(x^2+y^2)/(x+y)
=x^2+(x^2+y^2)/y÷(x^2+y^2)/(x+y)
=x^2+x/y+1
代入数据
=2×2-2+1
=3
答
x^2-y分之y(x-y)-x(x+y)除以x+y分之x^2+y^2=[(-x^2-y^2)/(x^2-y)]÷[(x^2+y^2)/(x+y)]=(x+y)/(y-x^2)=(2-1)/(-1-2^2)=-1/5如果此题是x^2-y^2分之y(x-y)-x(x+y)除以x+y分之x^2+y^2=[(-x^2-y^2)/(x^2-y^2)]÷[(x^2+y^2...
答
楼主，你描述清楚点，y分之y(x-y)-x(x+y)是[y(x-y)-x(x+y)]/y还是单个的除以y，然后后面又是除以x+y分之x^2+y^2，到底哪些是分子，哪些是分母啊，要不就弄个图片上来。