求(2X+Z-Y)/(X^2-XY+XZ-YZ)-(2X+Y+Z)/(X^2+XY+XZ+YZ)
问题描述：
求(2X+Z-Y)/(X^2-XY+XZ-YZ)-(2X+Y+Z)/(X^2+XY+XZ+YZ)
而且一些什么平方号啊,几次项的符号我也看不懂,所以麻烦各位用语言,或者用简单的一些数字叙述一下.
答
=[(X+Z)+(X-Y)]/[X(X-Y)+Z(X-Y)]-[(X+Y)+(X+Z)]/[X(X+Y)+Z(X+Y)]=[(X+Z)+(X-Y)]/[(X+Z)(X-Y)]-[(X+Y)+(X+Z)]/[(X+Z)(X+Y)]=1/(X-Y)+1/(X+Z)-1/(X+Z)-1/(X+Y)=1/(X-Y)-1/(X+Y)=(X+Y-X+Y)/(X方-Y方)=2X/(X方-Y方)