Question

qual o valor numerico da algebrica 2x ao cubo - 3x + 9 para: A X= - 2 B X = 0

Answer 1

$2x^3-3x+9\\\\\\ \text{Para}\ x=-2\\\\ 2(-2)^3-3.(-2)+9\\\\ 2(-2.-2.-2)+6+9\\\\ 2(4-2)+15\\\\ 2.(-8)+15\\\\ -16+15\\\\ \fbox{-1}\\\\\\ \text{Para}\ x=0\\\\ 2.(0)^3-3.0+9\\\\ 2.0-0+9\\\\ 0+9\\\\ \fbox{9}$