解方程组x2+y2=73x?3y=3

x2+y2=7①
3
x?3y=3②

由②得:y=

3
3
x-1? ③,

把③代入①得:

4
3
x2-
2
3
3
x-6=0,

x=

2
3
3
±
10
3
3
8
3

x1=

3
2
3
,x2=-
3

把x1=

3
2
3
代入③得,y1=
1
2

把x2=-

3
代入③得,y2=-2,

则原方程组的解是:

x1=
3
2
3
y1=
1
2
x2=?
3
y2=?2