Respuesta :

nadia2318116

Answer:

a(217)=638

Step-by-step explanation:

a(n) = a +(n-1)d

a=-1

d=-7+10=-4+7=3

a(n) = -10 +(n-1)3

a(217) = -10 +(217-1)3

         = -10+648

         =638

hope this helps