4/5 - 3k+8/5 = 1/2
(4/5 + 8/5) - 3k =1/2
12/5 - 3k =1/2
3k =5/12 - 1/2
3k = 5/12 - 6/12
3k= -1/12
k= -1/4
-(3r+1)/5 = 1/3
-3(3r+1) = 5
-9r - 3 =5
-9r =8
r = -8/9
萨芬三个巨款
4/5 - (3k+8)/5 = 1/2
[4-(3k+8)]/5=1/2
-3k-4=5/2
3k=-4-5/2=-13/2
k=-13/6
3r+1=-5/3
3r=-8/3
r=-8/9