Plis no 31 pake cara!!

U1 = 2
U5 = 162
S5 = .....?

U5 = U1×r⁴
162 = 2×r⁴ ===>>> r = 3

Sn = a(r^n - 1) / r-1
S5 = 2(3⁵-1) / 3-1
S5 = 242 cm

U5=a.r^4
162=2.r^4
r=3
U1=2
U2=6
U3=18
U4=54
U5=162
Maka Sn=tambahkan semua=242