Question

Determine : o 20° termo da PA (2,7....)

Answer 1

$r=a_2-a_1\\\\r=7-2\\\\r=5\\\\\\\\a_{20}=a_1+19r\\\\a_{20}=2+19(5)\\\\a_{20}=2+95\\\\\boxed{a_{20}=97}$

Answer 2

a20= a1+19r
a20= 2+19.5
a20= 2+ 95
a20= 97
O 20º termo é 97.