Question

Determine o 23º termo da PA (26, 20, 14, ...) *
- 100
- 106
112
- 68


Me ajudem pfv

Answer 1

Resposta:

$a_{1}=26\\\\ r=20-26=-6\\\\n=23\\\\a_{n}= a_{1}+(n-1)*r\\\\a_{n}= 26+(23-1)*(-6)\\\\a_{n}= 26+(22)*(-6)\\\\a_{n}= 26-132\\\\a_{n}= -106$