Then Zhang Lei's books are six times that of Li Xin.

Now Zhang Lei bought less 12-2= 10.

Four times that of Li Xin.

So Xin Li now has 10/(6-4)=5 copies.

As it turns out,

Li has 5-2=3 copies.

Zhang Lei has 3×6= 18 copies.

Equation:

Suppose Xin Li had X books before he bought them, because Zhang Lei's story books were six times as many as Xin Li's, so Zhang Lei had 6X books. After each of them bought two more books, Zhang Lei had 6X+2 books and Li Xin had X+2 books.

Because Zhang Lei bought four times as many books as Xin Li.

Then, 6X+2= 4(X+2)

So X=3.

So the result is that Zhang Lei has 18 books and Li Xin has 3 books.