resolsa a equacao C n,2 + C n1,3 = 6n
albertrieben:
o que é n1 ?
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Boa noite Lais
C(n,2) + C(n + 1,3) = 6n
C(n,2) = n!/2!(n-2)!
C(n,2) = n*(n - 1)/2
C(n + 1, 3) = (n + 1)!/3!(n - 2)!
C(n + 1, 3) = (n + 1)*n*(n - 1)/6
n*(n - 1)/2 + (n + 1)*n*(n - 1)/6 = 6n
(n - 1)/2 + (n + 1)*(n - 1)/6 = 6
3*(n - 1)/6 + (n + 1)*(n - 1)/6 = 6
(n - 1)*(3 + n + 1) = 36
(n - 1)*(n + 4) = 36
n² + 3n - 40 = 0
delta
d² = 9 + 160 = 169
d = 13
n = (-3 + 13)/2 = 10/2 = 5
C(n,2) + C(n + 1,3) = 6n
C(n,2) = n!/2!(n-2)!
C(n,2) = n*(n - 1)/2
C(n + 1, 3) = (n + 1)!/3!(n - 2)!
C(n + 1, 3) = (n + 1)*n*(n - 1)/6
n*(n - 1)/2 + (n + 1)*n*(n - 1)/6 = 6n
(n - 1)/2 + (n + 1)*(n - 1)/6 = 6
3*(n - 1)/6 + (n + 1)*(n - 1)/6 = 6
(n - 1)*(3 + n + 1) = 36
(n - 1)*(n + 4) = 36
n² + 3n - 40 = 0
delta
d² = 9 + 160 = 169
d = 13
n = (-3 + 13)/2 = 10/2 = 5
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