-2=a+b+c (1)
20=a-b+c (2)
x=3/2和1/3,y相同
则x=(3/2+1/3)/2=11/12,y=0
所以121a/144+11b/12+c=0
121a+132b+12c=0 (3)
(1)-(2)
2b=-22
b=-11
(1)+(2)
a+c=9
c=9-a
所以121a-1452+108-12a=0
109a=1344
a=1344/109
c=-363/109
-2=a+b+c (1)
20=a-b+c (2)
x=3/2和1/3,y相同
则x=(3/2+1/3)/2=11/12,y=0
所以121a/144+11b/12+c=0
121a+132b+12c=0 (3)
(1)-(2)
2b=-22
b=-11
(1)+(2)
a+c=9
c=9-a
所以121a-1452+108-12a=0
109a=1344
a=1344/109
c=-363/109