Question

Encontre o centésimo termo da P. A ( - 2, - 4,...)

Answer 1

a1 = -2
r = -4-(-2) = - 4+2 = -2
a100 = ??
n = 100

an = a1 + (n - 1)r
a100 = (-2) + (100 - 1) . (-2)
a100 = (-2) + 99 . (-2)
a100 = - 2 - 198
a100 = -200

:)

Answer 2

an = a1 + (n - 1) r            an = ?    a1 = -2    n = 100    r = -2

an = -2 + (100 - 1 ) (- 2)

an = -2 + (99) (-2)

an = - 2 + (- 198)

an = -200