Question

numero binomial (x 2)+(x 3) =35

Answer 1

Vamos lá

numero binomial C(x, 2)+ C(x, 3) = 35

x!/(x - 2)!2! + x!(x - 3)!3! = 35

x*(x - 1)/2 + x*(x - 1)*(x - 2)/6 = 35

3*x*(x - 1)/6 + x*(x - 1)*(x - 2)/6 = 35

x*(x - 1)* (3 + x - 2) = 210

(x - 1)*x*(x + 1) = 210 = 5*6*7

x = 6