Question

Considere a expressão A= x⁻²+x³+2x. Determine o valor numérico de A para x = -1/3.

Answer 1

$A= \frac{-1}{3} ^{-2}+\frac{-1}{3}^{3}} +2.\frac{-1}{3} \\ \\ A= \frac{3}{-1}^{2}-\frac{1}{27}-\frac{2}{3} \\ \\ A= -3^{2}-\frac{1}{27}-\frac{2}{3} \\ \\ A=9-\frac{1}{27}-\frac{2}{3} \\ \\ A= \frac{243-1-18}{27} \\ \\ A= \frac{224}{27}$