Question

Se A = x(x - 3) /2 , qual o valor de A para x = 15?

A)45

B)90

C)135

D)180

Answer 1

A = $\frac{x(x - 3)}{2}$

A = $\frac{15(15 - 3)}{2}$

A = $\frac{15 (12)}{2}$

A =  $\frac{180}{2}$

A = 90

Letra B