SOLUTION: How to solve the following logarithmic equations: 1.) x=log2(128) [with a base of 2] 2.) log2x=-4 [base of 2] 3.) log5(4x-3)=2 [base of 5] PLEASE HELP!

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: How to solve the following logarithmic equations: 1.) x=log2(128) [with a base of 2] 2.) log2x=-4 [base of 2] 3.) log5(4x-3)=2 [base of 5] PLEASE HELP!      Log On


   



Question 769922: How to solve the following logarithmic equations:
1.) x=log2(128) [with a base of 2]
2.) log2x=-4 [base of 2]
3.) log5(4x-3)=2 [base of 5]
PLEASE HELP!

Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
1) x = log2(128)
x = log2(2^7)
x = 7 log2 2
x = 7 (log2 2 = 1)
2) log2x = -4
x = 2^-4
x = 1/16
3) log5(4x - 3) = 2
4x - 3 = 5^2
4x - 3 = 25
4x = 25 + 3
4x = 28
x = 7
Hope this helps.
:-)