¿Podemos usar en una misma situación la fórmula para calcular el termino enésimo y la formula para calcular la suma de términos de una progresión geométrica?...

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

[2, 2.5)

(2.5, 3]

step-by-step explanation:

i think its these two not sure [2, 2.5)

(2.5, 3]

(x) - (y) = (1 + 4i)