SATOG2道数学题,牛人帮帮忙啦~~
P598就是有5个正方形卡片,其中一张不能放在最后,问有几种安排方式?
a,3a~~~
thefirstterminthesequenceaboveisa,andeachtermafterthefirstis3timestheprecedingterm,ifthesumoffirst5termsis605,whatisthevalueofa?我怎么算都是5啊,可答案是6!