Question

Determinar o 79o termo da PA ( 3, 9, 15, ... )

Answer 1

$\mathsf{r=a_{2}-a_{1}=9-3=6}\\\mathsf{a_{79}=a_{3}+76r}\\\mathsf{a_{79}=15+76\cdot 6}\\\mathsf{a_{79}=15+456}\\\huge\boxed{\boxed{\boxed{\boxed{\mathsf{a_{79}=471}}}}}$

Answer 2

resolução!

● Progressão Aritmética

r = a2 - a1

r = 9 - 3

r = 6

an = a1 + ( n - 1 ) r

an = 3 + ( 79 - 1 ) 6

an = 3 + 78 * 6

an = 3 + 468

an = 471

espero ter ajudado