Respuesta :

Answer:

-14

Step-by-step explanation:

You've got a(1)=20

a(1) means a(n) when n=1

the sequence is telling you to take the previous value of a(n), which is a(n-1) and subtract 17

then:

a(2) = a(1)-17 = 20 - 17 = 3

a(3) = a(2) - 17 = 3-17 = -14