Question

8^x-4=64(3^x) can anyone help

Answer 1

\[8^{x-4}\] or
\[8^x-4\]?

Answer 2

8^x-4 logarithmic function

Answer 3

so the x - 4 is all in the exponent?

Answer 4

yes

Answer 5

I get to the point x=log 64+4log 8/log 8-log3 how do I divide this?

Answer 6

ok then that makes it easier. there may be some snap way to do this but i think you simply have to take the log of both sides to get
\[(x-4)\ln(8)=\ln(64\times 3^x)=\ln(64)+x\ln(3)\] and then use algebra

Answer 7

ok I type this in my calculator and get the wrong answer the x=12.721 I dont get this

Answer 8

\[\ln(8) x -4\ln(8)=\ln(64)+\ln(3)x\]
\[3\ln(2)x-12\ln(2)=6\ln(2)+\ln(3)x\] first then the algebra

Answer 9

so you change the base

Answer 10

\[3\ln(2)x-\ln(3)x=18\ln(2)\]
\[x=\frac{18\ln(2)}{3\ln(2)-\ln(3)}\]

Answer 11

ok how do you divide this?

Answer 12

no i rewrote as follows:
\[\ln(8)=\ln(2^3)=3\ln(2)\] and
\[\ln(64)=\ln(2^6)=6\ln(2)\]

Answer 13

ok thanks i think i get it:)

Answer 14

i am not sure what you mean by "how do i divide" i don't know any of these numbers so if you want a decimal approximation i would put it in the calculator

Answer 15

yw