Step-by-step explanation:
This is a GEOMETRIC SEQUENCE so each term is multiplied by the common ratio , r, to get the next term
First term is -2 second term is 4 :
-2 * r = 4 shows the common ratio , r = -2
so an = a1 * r^(n-1)
an = -2 * (-2)^(n-1)
then when n= 7 a7 = -2 * ( -2)^6 = 128
