4m-3n+1=0 (1)
2m+6n=7 (2)
(1)*2+(2)
8m-6n+2+2m+6n=0*2+7
10m+2=7
10m=5
m=1/2
代入(2)
1+6n=7
6n=6
所以m=1/2,n=1