Question

Determine o 61 termo da P.A(530,510,490,470)?

Answer 1

r = a2 _ a1

r = 510 _ 530

r = _20

an = a1 + ( n _ 1 ) × r

a61 = 530 + ( 61 _ 1 ) × ( _20 )

a61 = 530 + 60 × ( _20 )

a61 = 530 _ 1200

a61 = _670