9^(x+5)=115 solve?

Question

9^(x+5)=115 solve?

priyar · Answer

Do you mean 
$$9^{x+5} = 115$$

study_buddy99 · Answer

I honk this is the answer

study_buddy99 · Answer

Think

anonymous · Answer

You set this up as a logarithmic equation. 
$$\log _{9}115=x+5 $$ 
2.15951167546=x+5
x=-2.84048832454

study_buddy99 · Answer

I got 109.7378886

umerlodhi · Answer

www.mathway.com go there and put in the equation and u got ur answer medal and fan me pliz

mtalhahassan2 · Answer

@study_buddy99 its -2.84048832454

umerlodhi · Answer

the answer is 115.2.3 -5

mtalhahassan2 · Answer

x= 2.15951167546-5
x=-2.84048832454

umerlodhi · Answer

the answer is 115/2.3 -5

anonymous · Answer

How did you calculate 109.73?

study_buddy99 · Answer

my calculator says so... one second

anonymous · Answer

are you sure it's giving log base 9?

umerlodhi · Answer

what mod warned me im not even sure if thats the correct answer

study_buddy99 · Answer

😀

anonymous · Answer

To change the base you want to use $$Log_b(x)=\frac{Log(x)}{Log(b)}$$
I think you did it in the wrong order maybe?

anonymous · Answer

where log can be anything. Calculators usually have $$Log_e:=Ln, Log_{10}$$

anonymous · Answer

Log can be base of anything that is.

study_buddy99 · Answer

now I got the answer -4.19

anonymous · Answer

I get $$\frac{Log[115]}{Log[9]}=2.1595$$, So 2.1592-5= -2.8405

study_buddy99 · Answer

I see, I was doing it backwards

anonymous · Answer

:)

fibonaccichick666 · Answer

my two cents, I'd rather avoid change of base and just use natural log and properties of logs to solve.  My first step would be $$9^{x+5}=115\ln(9^{x+5})=ln(115)\(x+5)ln9=ln(115)$$  From there just solve for x.  May save you time in the future :)

anonymous · Answer

Also a good plan, and notice $$x+5=\frac{ln(115)}{ln(9)}$$ shows up in @FibonacciChick666's solution, so you don't need to remember change of base formula, just derive it!