Question

Quantoa termos tem uma pa (-5,0,5,10...805)

Answer 1

$\Large\boxed{\begin{array}{l}\sf a_n=a_1+(n-1)r\implies n=\dfrac{a_n-a_1}{r}+1\\\\\sf\\\sf n=\dfrac{805-(-5)}{5}+1\\\\\sf n=\dfrac{805+5}{5}+1\\\\\sf n=\dfrac{810}{5}+1\\\\\sf n=162+1\\\sf n=163\end{array}}$