解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66
问题描述：
解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66
答
2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66设x+y=a,x-y=b,原方程化为2/a+5/b=18 -----1(1)9/a+10/b=66 -------(2)(2)-(1)*2 得5/a=30 所以a=1/6 ；代入(1)式得b =5/6于是有x+y=1/6x-y=5/6两式相加得2x=1,所以x=1/2,代...