Question

O vigésimo termo da P.A(1,3,5,7,9,...)é

Answer 1

a20=1+19*2
a20=1+38
a20=39

Answer 2

(1,3,5,7,9,...)

An=A1+(N-1).R
Onde, A1= 1 / N=20 / R=2

A20=1+(20-1).2
A20=1+19.2
A20=1+38
A20=39