Question

(2n + 1)² + (n + 2)² + 2(n+1)(n-1) é igual a?

Answer 1

resposta =
(2n+1)*(2n+1)+(n+2)*(n+2)+2(n+1)*(n-1)=
4n²+2n+2n+1+n²+2n+2n+4+[(2n+2)*(n-1)]=
4n²+4n+1+n²+4n+4+2n²-2n+2n-2=
organizando=
4n²+n²+2n²+4n+4n-2n+2n+1+4-2=
7n²+8n+3

resposta:
7n²+8n+3

Answer 2

(2n + 1)² + ( n + 2)² + 2 (n + 1) (n-1) =

(4n² + 4n + 1) + (n² + 4n + 4) + 2 (n² - 1) = 

(4n² +4n + 1) + (n² + 4n + 4) + 2n² - 2 = 

4n² + 4n + 1 + n² + 4n + 4 + 2n² - 2 =

7n² + 8n + 3 =