Question

Calculati, algebra combinatorica simpla

Answer 1

Răspuns:

Aₙ⁶=n!/6!=n*(n-1)(n-2)...(n-5)

Aₙ⁵=n!/5!=n*(n-1)(n-2)...(n-4)

Aₙ⁴=n!(n-1)(n-2)(n-3)

(Aₙ⁶+Aₙ⁵)/Aₙ⁴=

[n*(n-1)(n-2)...(n-5)+n(n-1)(n-2)...(n-4)]/(n!(n-1)(n-2)...(n-3)]=factor   comun=

n*(n-1)*(n-2)...(n-5)[1+(n-4)]/n(n-1)*(n-2)(n-3)=simplifici prin n(n-1)(n-2)(n-3)=

(n-4)(n-5)(n-3)

Explicație pas cu pas: