Question

se de=n(n-3),calcule o
valor de d para n=15

Answer 1

$n(n - 3) \\ 15(15 - 3) \\ 15 \times 12 = 180$

Answer 2

D = \frac{n(n-3)}{2}

Para n = 15 temos:

D = \frac{15(15-3)}{2}

D = \frac{15 * 12}{2}

D = \frac{180}{2}

D = 90