Question

Considere o polinômio 3x² − 4x³ + x − 2x² + 7x³ − 12 + x³ . Calcule o valor numérico deste polinômio sabendo que x = 3.

Answer 1

    $3x^2-4x^3+x-2x^2+7x^3-12+x^3=$

$=-4x^3+x^3+7x^3+3x^2-2x^2+x-12=$

$=-3x^3+7x^3+x^2+x-12=$

$=4x^3+x^2+x-12$

Seja  $x=3$ :

    $4\times3^3+3^2+3-12=$

$=4\times27+9+3-12=$

$=108+9+3-12=$

$=117+3-12=$

$=120-12=$

$=108$