问题:

试题 题型:未知 难度等级:

设数列{an},{bn}都是等差数列,若a1+b1=7,a3+b3=21,则a5+b5=_________

设数列{an},{bn}都是等差数列,若a1+b1=7,a3+b3=21,则a5+b5=_________

可能感兴趣的题目: