解:?$(1)k^3_{-10}=(-10)×(-9)×(-8)=-720$?
?$(2)K^1_{-5}=-5$?;?$K^2_{-5}=(-5)×(-4)=20$?
?$K^3_{-5}=(-5)×(-4)×(-3)=-60$?;?$K^4_{-5}=(-5)×(-4)×(-3)×(-2)=120$?
?$K^5_{-5}=(-5)×(-4)×(-3)×(-2)×(-1)=-120$?
當?$n≥6$?時,?$K^n_{-5}=0$?
∴?$K^n_{-5}$?的最大值是?$120$?,此時?$n=4$?