E
etete


Giải Pt
a, $\dfrac{$P_{n+5}$}{(n-k)!}$ \leq 60 $A_{n+3}^{k+2}$
b, $x^2$ -$C_4^x$ x+ $C_3^2$ $C_3^1$ =0
a, $\dfrac{$P_{n+5}$}{(n-k)!}$ \leq 60 $A_{n+3}^{k+2}$
b, $x^2$ -$C_4^x$ x+ $C_3^2$ $C_3^1$ =0
Last edited by a moderator: