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解方程组3/(x+y)+1/(x-y)=82/(x+y)-1/(x-y)=7

题目详情
解方程组3/(x+y)+1/(x-y)=8 2/(x+y)-1/(x-y)=7
▼优质解答
答案和解析
设A=1/(x+y) B=1/(x-y)
即3A+B=8
2A-B=7
解得A=3 B=-1
即1/(x+y)=3 则x+y=1/3
1/(x-y)=-1 则x-y=-1
解得 x=-1/3 y=2/3