Question

determine a20 na PA em que a1= -3 e r= 5

Answer 1

$a_n=a_1+(n-1)*r \left\{\begin{array}{ccc}a_1=-3\\ r=5\\n=20}}\end{array}\right \\\\ a_{20}=-3+(20-1)*5 \\\\ a_{20}=-3+19*5 \\\\ a_{20}=-3+95 \\\\ a_{20}=92 \\\\\\ Resposta \to \boxed{\boxed{a_{20}=92}}$

Espero ter ajudado!

Answer 2

an=a1+(n-1).r
a20= -3+(20-1).5
a20= -3+19x5
a20= -3+ 95
a20= 92