Dik :DG = U4=16 U1=2 Dit : a, r, S5 Minta bantuanya dong Ko r nya = 2 akar 2

geometri ya??
Un = ar^(n-1)
U4 = 2.r^3 = 16
r^3 = 8
r^3 = 2^3
r = 2

gkda akar 2 ???

Dik: U1=2 ; U4=16
Dit: a, r, S5
Penyelesaian:
a. a=2
b. U1=2➡a
U4=16➡ar^3
ar^3=16
2r^3=16
r^3=16/2
r^3=8
r=2
c. S5=a(r^n - 1)/r-1
=2 (2^5-1)/2-1
=2 (32-1)/1
=2 (31)/1
=62/1
S5=62