Step-by-step explanation:
a scale factor of 2 means that the new shape is twice the size of the original. A scale factor of 3 means that the new shape is three times the size of the original.
this should help I have it step
An = a1 * r^(n-1)
-405 = -5*3^(n-1)
3^(n-1) = 81
3^4 = 81 so n-1 = 3 and n = 4
Sn = S4 = -5 (1 - 3^4) / ( 1 - 3) = 400 / -2 = -200 Answer
