Question

In 4^x+3=8^x-1, what is the value of x?

Answer 1

@dan815 how do you go about doing this?

Answer 2

\[\ln4^x+3=8^x-1 \]?

Answer 3

I think it is
\[ 4^{x+3}=8^{x-1}\]

Answer 4

Ok that is much easier to do then lol

Answer 5

yes then it is..

Answer 6

No, the first one. @kirbykirby

Answer 7

It's actually:
\[4^{x} + 3 = 8^{x} - 1\]

Answer 8

I bet kirby is thinking Ln, and you are thinking in

Answer 9

Without the ln.

Answer 10

Yeah.

Answer 11

ooh ok lol

Answer 12

if you are looking for integer solution ... then factorize 8^x - 1 ... and use divisibility, it will give you one solution x=1

Answer 13

for x=2 and higher ... show that 8^x-1 > 4^x +2 hence no solution exist. for negative x, use similar argument.

Answer 14

Oh, thank you.