$=\frac{8\cdot 4!}{6!}$
Cancel the factorials $\frac{n!}{\left(n+m\right)!}=\frac{1}{\left(n+1\right)\cdot \left(n+2\right)\cdots \left(n+m\right)}$$=\frac{8}{5\cdot 6}$
Cancel $\frac{8}{5\cdot 6}:{\quad}\frac{4}{5\cdot 3}$$=\frac{4}{5\cdot 3}$
Multiply the numbers: $ 5\cdot 3=15$$=\frac{4}{15}$