Question

oh gosh....please... Find the sum of a finite geometric sequence from n = 1 to n = 7, using the expression –4(6)^(n – 1)

Answer 1

see this about geometric series: http://mathworld.wolfram.com/GeometricSeries.html

from the expression –4(6)^(n – 1), a=-4 and r=6

use the eqn from the link to calculate the sum. good luck :)