diketahu U3=12 dan U5=48 dari barisan geometri. maka nilai dari U7=..... *mohon bantuannya

U3 = ar^2 = 12
U5 = ar^4 = 48

U5/U3
= ar^4 / ar^2 = 48/12
r^2 = 4
r = 2

U3 = ar^2 = 12
a × 2^2 =12
a × 4 = 12
a = 3


U7 = ar^6
= 3 × 2^6
= 3 × 64
= 192

U5 = U1.r^4 = 48
U3 = U1.r^2 = 12
Un = U1 × r^n-1

r = U5/U3
U1.r^4 = 48/U1.r^2 = 12
r^2 = 4
r = 2

Subs r = 2
12 = U1 × r^2
12 = U1 × 2^2
12 = U1 × 4
U1 = 12/4
U1 = 3

U7 = 3 × 2^6
=> 3 × 64 = 192