Intermediate Algebra question in comments, Please help :)
\[64^{3x}=16^{x+1}\]
Hint: Try to make the base a common number ,Can you guess what is it ?
4
iv'e gotten to \[(3x)\log64=(x+1)\log16 \] using the method i was taught.
im not sure what to do after this though
i have to provide the value of x and an estimate to the fourth decimal place
Great So by making the base similar , we will get : \[\Large 4^{3(3x)} = 4^{2(x+1)} \] Since the base = base ,therefore the power = power . 3(3x)=2(x+1) 9x=2x+1 7x=1 x=1/7
okay i see
k, thx
Back :3
:D
\[\Large (3x)\log64=(x+1)\log16\] Combine similar terms , \[\Large \frac{(3x)}{(x+1)}=\frac{\log16}{\log64}\] Here is a hint that i always do to prevent confusing , Let Log16/Log64 = m therefore 3x/x+1=m then \[\large xm+m=3x\] Now combine again the x \[\Large xm-3x=m\] Take the x common , \[\Large x(m-3)=m\] Then \[\Large \color{Red} X=\frac{m}{m-3}\]
Now Substitute The value of m and get X :) P.S:Letting Log16/Log64 = m ,Is not necessary ..I did it only to abbreviate it
You got what i said xD ?
sry, i was away for a sec. im not quite sure i understood what u mean by m
Ignore that part ,Just do the Multiply them by each other .
multiply what by what?
sry im slow
lol
(log16/log64)(x+1)=3x
That ^
i see
so what do i do after that?
combine the x together
and take x common Then Calulate it
calculate
\[\large 64^{3x}=16^{x+1}\] \[\large (4)^{3(3x)}=4^{2(x+1)}\] \[\large 9x=2x+2\] \[\large 7x=2\] \[\large x=\frac{2}{7}\]
I already did that !
?, two different answers though.
Why would you use logs when you can just do that.
x=1/7
He is right ,i missed the 2 7x=2
That's wrong. YOu didn't expand/distribute properly.
i need it in the format of log(a)/log(b) i think
*sigh
\[64^{3x}=16^{x+1}\]
\[(4^{3})^{3x}=(4^{2})^{x+1}\]
Then \[x=\frac{2}{7}\] \[\log x=\log \frac{2}{7}\] \[\frac{\log x}{\log \frac{2}{7}}=1\]
\[4^{9x}=4^{2x+2}\]
\[9x=2x+2\] 7x=2 x=2/7
\[\log x=\log \frac{2}{7}\] \[\log x=\log 2 -\log 7\] I don't know why you need it in that form and you can't get it into that form if you want x as the subject.
@sgta101
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