Question

P(2/3)=x(elevado a 3) + x - 1

Answer 1

basta substituir x por 2/3:

$P( \frac{2}{3} ) = {( \frac{2}{3} )}^{3} + \frac{2}{3} - 1 \\ \\ P( \frac{2}{3} ) = \frac{8}{27} + \frac{2}{3} - 1 \\ \\ P( \frac{2}{3} ) = \frac{8}{27} + \frac{18}{27} - \frac{27}{27} \\ \\ P( \frac{2}{3} ) = \frac{8 + 18 - 27}{27} = - \frac{1}{27}$

nenhuma das alternativas está correta