please please someone help!! im confused on the parentheses part. i will give brainliest and 20 points

(first term)

a=27(4th term)

T4= a x r^3 = 64

substituting a as 27 in T4

27 x r^3 = 64

r^3 = 64/27

r=4/3

so; a=27, r=4/3

using the general formula of geometric progression,

a x r^n-1

substitute:.

27 x 4/3^n-1

= 27(4/3)^n-1

(C) HOPE THIS HELPS!

can i see the following ?

step-by-step explanation: