x/m+2与y/m-2的和等于4m/m方-4,则x 等于?y等于?
问题描述：
x/m+2与y/m-2的和等于4m/m方-4,则x 等于?y等于?
答
x/(m+2)+y/(m-2)=4m/(m^2-4)
[x(m-2)+y(m+2)]/(m^2-4)=4m/(m^2-4)
x(m-2)+y(m+2)=4m
m(x+y)-2(x-y)=4m [式中结果不含x,y,所以2(x-y)=0,即x=y]
m(x+y)=4m
2mx=4m
x=2
所以x=y=2