Question

Determine o 20º termo de cada sequência
a) (4,7,10,13...)
b) (3,1,-1,-3,-5...)

Answer 1

a) (4,7,10,13...)
a20=a1+(19).r = 4 +19.3= 4 +57 = 61

b) (3,1,-1,-3,-5...)
a20=a1+(19).r = 3 +19.-2= 3 -38= -35