解方程(x2+1)*(y2+1)=10、(x+y)*(xy-1)=3
问题描述:
解方程(x2+1)*(y2+1)=10、(x+y)*(xy-1)=3
答
(x²+1)(y²+1)=10x²y²+x²+y²+1=10x²y²-2xy+1+x²+y²+2xy=10(xy-1)²+(x+y)²=10[(xy-1)+(x+y)]²-2(x+y)(xy-1)=10(x+y)(xy-1)=3代入[(xy-1)+(x+y)]...