Question

Solve for x.
4^(9x) = 9^(x+4)

Write the exact answer using base-10 logarithms.

Answer 1

9x log(4) = (x+4) log(9)

log(4) x+4
----- = ----
log(9) 9x

Answer 2

the right goes to; (1/9) + (4/9x)

Answer 3

log(4) 1 4
----- - --- = ---
log(9) 9 9x


4
9x = -----------------
(log(4)/log(9)) - (1\9)



4
x = ----------------------
9 [(log(4)/log(9)) - (1\9)]

Answer 4

maybe :)

Answer 5

I see where you're going with this. But when I punched the thing into wolframalpha. I get a different answer. its

x = 4 log(3) / (9log(2) - log(3))

Answer 6

Do you have any idea how it came to that solution?

Answer 7

wolfram prolly simplified it; or i just plain missed it :)

Answer 8

log(3)?

Answer 9

yes log(3)

Answer 10

log(4) and log(9) are the only ones I see ..... cant tell why they got that

Answer 11

yea that is why im confused :/

Answer 12

thats the root; for x ... which might be the same thing have to look at

Answer 13

ah okay thanks for the help :)

Answer 14

http://www.wolframalpha.com/input/?i=y+%3D+%284^%289x%29%29+and+y%3D9^%28x%2B4%29

is what it gives me

Answer 15

same thing in exact form lol

Answer 16

i think you inputted it wrong

this is what i got
http://www.wolframalpha.com/input/?i=4^%289x%29+%3D+9^%28x%2B4%29

Answer 17

we got the same results ..... the log(3) stuff

Answer 18

oh i didnt notice. lol

Answer 19

so is that right or is the answer you gave me right? or are they the same?

Answer 20

i cant see where mine is off; but i dint try to simplify nuthin; try thers, they seem to be smarter than me :)

Answer 21

but I dont know how they got there >.<

Answer 22

check out this one, in the other forms:
http://www.wolframalpha.com/input/?i=4%2F%289%28%28log%284%29%2Flog%289%29%29+-+%281%5C9%29%29&a=*FunClash.log-_*Log10.Log-

Answer 23

so they are the same :)