Question

Determine o 20° termos da PEA 5156 e 61

Answer 1

$\mathtt{R = A_2 - A_1} \\ \mathtt{R = 56 - 52} \\ \mathtt{R = 5}$

$\mathtt{A_n = A_1 + (n-1)~.~R} \\ \mathtt{A_{20} = 51 + (20-1)~.~5} \\ \mathtt{A_{20} = 51 + 19~.~5} \\ \mathtt{A_{20} = 51 + 95} \\ \mathtt{A_{20} = 146}$