由（2）得5a-2b=52b=5a-5b=(5a-5)/2 (3)把（3）代入（1）得7(5a-5)/2+3a/2=227(5a-5)+3a=22*235a-35+3a=4438a=79a=79/38 代入（3）得b=(5a-5)/2b=(5*79/38-190/38)/2b=205/38*1/2b=205/76故a=79/38,b=205/76...