Question

Determine o quinto termo na p.g 5,15,45

Answer 1

Ora, repare que 45/15 = 15/5 = 3

assim,

5, 3*5 = 15, 15*3 = 45, 45*3 = 135, 135*3 = 405

Answer 2

a1=5

a2=15

a3=45

r=a2/a1=a3/a2=15/5=45/15

r=3

a5=a1×q^(n-1)

a5=5×3^(5-1)

a5=5×3^4

a5=5×81

a5=405