Question

o décimo termo da p.a (1,3,5,7,9)?

Answer 1

r = 3-1 = 2
a1 = 1

an = a1 + (n-1) × r
a10 = 1 + (10-1) × 2
a10 = 1 + 9×2
a10 = 1+18
a10 = 19

Resposta: 19.

Answer 2

an = a₁ + (n - 1) * r

r = a₂ - a₁

r = 3 - 1

r = 2

a₁₀ = a₁ + (10 - 1) * r

a₁₀ = 1 + (10 - 1) * 2

a₁₀ = 1 + (9) * 2

a₁₀ = 1 + 18

a₁₀ = 19