题目

(理)已知两圆⊙C1:x2+y2+D1x+E1y-3=0和⊙C2:x2+y2+D2x+E2y-3=0都经过点A(2,-1),则同时经过点(D1,E1)和点(D2,E2)的直线方程为A.2x-y+2=0        B.x-2y-2=0        C.x-2y+2=0          D.x+y-2=0 答案：(理)解析:∵⊙C1与⊙C2都过A(2,-1),∴即∴过(D1,E1)和(D2,E2)的直线为2x-y+2=0.答案:A

查看本题答案和解析