当(x-y)/(x+y)=2时,代数式(x-y)/(x+y)-(2X+2Y)/(X-Y)的值是快.过时不候

当(x-y)/(x+y)=2时,代数式(x-y)/(x+y)-(2X+2Y)/(X-Y)的值是快.过时不候
当(x-y)/(x+y)=2时,代数式(x-y)/(x+y)-(2X+2Y)/(X-Y)的值是
快.过时不候

当(x-y)/(x+y)=2时,代数式(x-y)/(x+y)-(2X+2Y)/(X-Y)的值是快.过时不候
因为(x-y)/(x+y)=2 所以(x+y)/(x-y)=1/2；
(2X+2Y)/(X-Y)=2*[(x+y)/(x-y)]=1
所以答案为2-1=1

等-2

原式=2-2(1/2)=2-1=1