解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66

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解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66

解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66
解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66

解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66
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=1/6
x-y=5/6
两式相加得2x=1,所以x=1/2,代入任一方程得y=-1/3
即原方程的角是
x=1/2
y=-1/3