Question

a expressão (2n+1)+(n+2)+2(n+1)(n-1) e igual a?

Answer 1

(2n +1)+(n +2) +2.(n+1).(n-1)
2n +1 +n +2 +2.(n² -n +n -1)              obs: cancela -n e +n
2n+n +1+2 +2n² -2                             obs: cancela -2 e +2
2n² +3n +1=0
fórmula de Bháskara:
Δ= b² -4.a.c
Δ= 3² -4.2.1
Δ= 9 -8
Δ= 1

n= -b ±√Δ /2.a
n= -3 ±√1 /2.2
n= 9 ±1 /4

n'=9+1 /4
n'=10 /4               :2 (simplificando por 2)
n'= 5 /2

n''= 9-1 /4
n''= 8/4
n''= 2