suku ke-2 dan suku ke-5 dari barisan geometri 6 dan 162 suku ke-8 ?

Langsung aja y

r = (U5 : U2)^1/(5-2)
r = (162 : 6)^⅓
r = 27^⅓
r = 3

U8 = U5 × r³
U8 = 162 × 3³
U8 = 162 × 27
U8 = 4.374

Semoga berguna +_+

U2 = 6 -> U2 = ar^n-1
                  6 = ar ^2-1
                  6 = ar
U5 = 162 -> U5 = ar^n-1
                    162 = ar^5-1
                    162 = ar^4

ar^4 = 162
__________  =
ar = 6

r³ = 27
r = 3

a × r = 6
a × 3 = 6
a = 6/3
a =2

U8 = ar^n-1
      = 2 × 3^8-1
      = 2 × 3^7
      = 2 × 2187
      = 4.374