Question

Find the first, fourth, and eighth terms of the sequence. A(n) = –5 • 3n–1 please help me

Answer 1

first A(1) = -5

fourth A(4) = -135

eight A(8) = -10,935

Explanation:

`A(n)=-5\cdot3^(n-1)\\\\\text{put n = 1, n = 4 and n = 8 to the expression}\\\\A(1)=-5\cdot3^(1-1)=-5\cdot3^0=-5\cdot1=-5\\\\A(4)=-5\cdot3^(4-1)=-5\cdot3^3=-5\cdot27=-135\\\\A(8)=-5\cdot3^(8-1)=-5\cdot3^7=-5\cdot2,187=-10,935`