Question

Considerando os polinômios A= 4a^3 -2a^2 +3a - 1 e B= 5a^2 -6a +5 , calcula A – B e marca a resposta correta:

A) 4a^3 + 3a^2 +9a - 6

B) -4a^3 -5a^2 +3a -6

C) -7a^2 +9a -6

D) -a^3 +3a^2 +9a -6

E) 4a^3 -7a^2 +9a -6

Answer 1

Resposta:

$A=(4a^{3}-2a^{2} +3a-1)\\\\ B=5a^{2} -6a+5\\ \\ \\ A-B=(4a^{3}-2a^{2}+3a-1)-(5a^{2}-6a+5)\\ \\Inverta~os~sinais~do~polinomio~B,~agrupe~os~termos~semelhantes\\\\ e~efetue:\\ \\ 4a^{3}-2a^{2}-5a^{2}+3a+6a-1-5=4a^{3}-7a^{2}+9a-6\\ \\ \\ Resposta:~~alternativa~E)~~4a^{3}-7a^{2}+9a-6$