Question

determine o termo A30 da PA ( 2,11,20,...)

Answer 1

$a_n=a_{30}=?\\ a_1=2\\ n=30\\ r=11-2=9\\ \\ a_n=a_1+(n-1)r\\ \\ a_{30}=2+(30-1)(9)\\ a_{30}=2+(29)(9)\\ a_{30}=2+261\\ \\ a_{30}=263$

Answer 2

P.A (2,11,20,.. )

Razão=9

Pn=a1+(n-1)*r

P30=2+(30-1)*9

P30=2+29*9

P30=2+261

P30=263

Resposta: A30 = 263