Answer:
183
Step-by-step explanation:
it is clearly a geometric sequence.
the common ratio of multiplication factor is -3.
3 × -3 = -9
-9 × -3 = 27
27 × -3 = -81
-81 × -3 = 243
the sum of these first 5 terms is
3 - 9 + 27 - 81 + 243 = 183
FYI - there is a formula to add the first n terms of a geometric sequence :
Sn = a1(1 - r^n)/(1 - r)
if r < 1 (like in our case -3).
in our case
S5 = 3(1 - (-3)⁵)/(1 - -3) = 3(1 - -243)/4 / 3×244/4 = 3×61 = 183
