SOLUTION: the problem is: 3^4x-5 = 9^7x i forget whether or not the 3 and the 9 are the same base 10, or whether you need to use the change of base formula and I can't find an example lik

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: the problem is: 3^4x-5 = 9^7x i forget whether or not the 3 and the 9 are the same base 10, or whether you need to use the change of base formula and I can't find an example lik      Log On


   

Question 376321: the problem is: 3^4x-5 = 9^7x
i forget whether or not the 3 and the 9 are the same base 10, or whether you need to use the change of base formula and I can't find an example like this is my notes.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
3%5E%284x-5%29=9%5E%287x%29 Start with the given equation.


3%5E%284x-5%29=%283%5E2%29%5E%287x%29 Rewrite 9 as 3%5E2


3%5E%284x-5%29=3%5E%2814x%29 Multiply the exponents.


4x-5=14x Since the bases are equal, the exponents are equal.


4x=14x%2B5 Add 5 to both sides.


4x-14x=5 Subtract 14x from both sides.


-10x=5 Combine like terms on the left side.


x=%285%29%2F%28-10%29 Divide both sides by -10 to isolate x.


x=-1%2F2 Reduce.


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Answer:

So the solution is x=-1%2F2


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim