小练习
1.在等差数列{an}中,若a6=a4+6,则公差d =________. 2.已知48,a,b,c,-12是等差数列,则a =____, b=____, c=____. 3.已知等差数列{an}的公差为-1,且a1+a3+a5 +…+a99=100,则a2+a4+a6+…+a100=_________.
33
18
50