Question

quantos termos a P.A a1=2,an=256 ea razao e 2

Answer 1

a1 = 2
r = 2
an = 256
n = ?

an = a1 + (n-1).r
256 = 2 + (n-1).2
256 = 2 + 2n - 2
256 = 2n
n = 256/2
n = 128