2025届高考数学一轮复习专项练习课时规范练29等差数列

课时规范练29　等差数列基础巩固组1.已知等差数列{an}的前n项和Sn满足S10-S3=42,则a7的值是(　　)A.3 B.6 C.7 D.92.已知数列{an}满足an+1=an+2且a2+a4