Question

Find a39 of the arithmetic sequence given a1 = -28 and d = -4.

Answer 1

Hello !

$a_{n} = a_{1} + (n - 1) \times d$

$a_{39} = - 28 + (39 - 1) \times ( - 4) = - 28 + 38 \times ( - 4) = - 180$