SOLUTION: How do you solve problems like this? 324=4(3^n-1) thank you

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Question 315228: How do you solve problems like this?
324=4(3^n-1)
thank you
Found 2 solutions by nerdybill, malaydassharma:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
I'm assuming the (n-1) is the exponent -- if not, please write back.
.
324=4%283%5E%28n-1%29%29
81=+3%5E%28n-1%29
log%283%2C81%29=+n-1
log%283%2C3%5E4%29=+n-1
4=+n-1
5=+n

Answer by malaydassharma(59) About Me  (Show Source):
You can put this solution on YOUR website!
Problem is not clear, so two solution is possible.
Solution 1:
4%283%5En-1%29=324
3%5En-1=81
3%5En=80
nlog%2810%2C3%29=log%2810%2C80%29
n=log%2810%2C80%29%2Flog%2810%2C3%29

Solution 2:
4%283%5E%28n-1%29%29=324
3%5E%28n-1%29=81
3%5E%28n-1%29=3%5E4
n-1=4
n=5