等差数列5,8,11.与等差数列3,8,13.都有100项,那么这两个数列相同的项共有多少项

a[n]=3n+2
b[n]=5n-2
a[2]=b[2]=8
当他们增加3，5的公倍数后会再次相等
a[2+5k]=15k+8
b[2+3k]=15k+8
2+5k≤100
2+3k≤100
k最大19
k从0到19，共20项
{an序号,bn序号,项值}
{2,2,8}
{7,5,23}
{12,8,38}
{17,11,53}
{22,14,68}
{27,17,83}
{32,20,98}
{37,23,113}
{42,26,128}
{47,29,143}
{52,32,158}
{57,35,173}
{62,38,188}
{67,41,203}
{72,44,218}
{77,47,233}
{82,50,248}
{87,53,263}
{92,56,278}
{97,59,293}

数列1是an=3n+2 ,n=1,2.100
数列2是bn=5m-2,m=1,2.100
令an=bm,
即3n+2=5m-2,
5m-4=3n
5m得出的值,其尾数一定是0或5,5m-4的尾数一定是1或6
等差数列1的第100项是302,等差数列2的第100项是498
所以相同的项有第一个数列的第2,7,12,17,22,27,32,37,
42,47,52,57,62,67,72,77,82,87,92,97项共20项,