Question

{1/(x+y)+1/(y+z)=6/5,1/(y+x)+1/(z+x)=7/12,1/(z+x)+1/(x+y)=3/

Answer 1

1/(x+y)+1/(y+z)=6/5 ①

1/(y+z)+1/(z+x)=7/12 ② 应该是这样1/(z+x)是1/(y+z)

1/(z+x)+1/(x+y)=3/4.③

①-③得

1/(y+x)-1/(z+x)=6/5-3/4=9/20 ④

②+④得

2/(y+x)=7/12+9/20=62/60

1/(x+y)=31/60 ⑤

分别代入①、③得

1/(y+z)=6/5-31/60=41/60 ⑥

1/(z+x)=3/4-31/60=14/15 ⑦

由⑤⑥⑦分别转化可得

x+y=60/31

y+z=60/41

z+x=15/14

三式相加得

x+y+z= ⑧

用⑧分别减去三式就得出x y z了

你自己算一下,不明白再追问