+0  
 
0
245
2
avatar

$${log}_{10}\left({{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{x}}\right) = {log}_{10}\left({\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{12}}\right)$$

Guest Aug 18, 2015

Best Answer 

 #2
avatar+17743 
+5

Since both logs are to the base 10, take both sides of the equation to the power of 10:

10log10 (x^2 - 2x )  =  10log10 (2x + 12)

Since 10log10 (Anything)  =  Anything

--->   x2 - 2x  =  2x + 12

--->   x2 - 4x - 12  =  0

--->   (x - 6)(x + 2)  =  0

--->   x = 6  or  x = -2

In problems like these, you need to check all the answers; they do work!

Could you just cross out the log10 from both sides? -- So long as all of both sides are in log form, yes!

geno3141  Aug 18, 2015
 #1
avatar
0

Someone? please

Guest Aug 18, 2015
 #2
avatar+17743 
+5
Best Answer

Since both logs are to the base 10, take both sides of the equation to the power of 10:

10log10 (x^2 - 2x )  =  10log10 (2x + 12)

Since 10log10 (Anything)  =  Anything

--->   x2 - 2x  =  2x + 12

--->   x2 - 4x - 12  =  0

--->   (x - 6)(x + 2)  =  0

--->   x = 6  or  x = -2

In problems like these, you need to check all the answers; they do work!

Could you just cross out the log10 from both sides? -- So long as all of both sides are in log form, yes!

geno3141  Aug 18, 2015

14 Online Users

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.