Question

determine a formula do termo geral de cada PA:

a) (2,7...)

b (-1,5...)

Answer 1

an = a1 + ( n - 1 ) . r

r = a2 - a1

a) (2,7,...)

an = 2 + ( n - 1 ) . 5

an = 2 + 5n - 5

an = 5n - 3

b) (-1,5,...)

an = -1 + ( n - 1 ) . 6

an = -1 + 6n - 6

an = 6n - 7