2分之x+y+2分之x-y=6 3(x+y)-5(x-y)=4令x+y=a x-y=b∴a/2+b/2=6a+b=12 ①3a-5b=4 ②①×5+②得：5a+3a=60+48a=64a=8b=4∴x+y=8 x-y=4∴x=6 y=2
