Question

qual o vigésimo terceiro termo da PA(-45,-41,-37-,-33,...)

Answer 1

$a_{23} = a_{1} + 22r$

sabendo que:

$r = - 41 + 45 = 4$

$a_{1} = - 45$

então:

$a_{23} = - 45 + 22 \times 4 \\ a_{23} = - 45 + 88 \\ a_{23} = 43$

Answer 2

-45, -41, -37, -33, -29, -25, -21, -17, -13, -9, -5, -1, 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43