Question

Resolva a equação x + 3x + 5x + 7x + ... + 99x = 1. Tarefa sobre PA

Answer 1

a1 = x
an = 99x
r = 2x
Sn = 1
n = ?
x = ?

an = a1 + (n - 1).r
99x = x + (n - 1).2x
99x = x + 2xn - 2x
99x = -x + 2xn
2xn = 99x + x
2xn = 100x
n = 100x/2x
n = 50

Sn = (a1 + an).n/2
1 = (x + 99x).50/2
100x.25 = 1
2500x = 1
x = 1/2500
 
Resposta: x = 1/2500