Solve for x
2=log(5x+12)

Question

Solve for x
2=log(5x+12)

asnaseer · Answer

make use of the fact that if:$$\log_ab=c$$then this implies that:$$b=a^c$$

ria23 · Answer

I did one similar to this one, it had a log base of 3... That became my exponent~ 
I don't have a base... That automatically means it's 10 right?

hartnn · Answer

correct :)

ria23 · Answer

So I would set it up
$$5x+12=10^{2}$$?

asnaseer · Answer

perfect! :)

ria23 · Answer

Would that take me to 
$$5x-88=0 $$
then factor 88 and find x from there?

hartnn · Answer

factoring 88 might not be useful
add 88 on both sides first

asnaseer · Answer

then divide both sides by 5 and you are done :)

ria23 · Answer

So I subtract 100 from both sides then add 88 on both?

hartnn · Answer

yes. 

5x+12 = 100

5x +12-100 = 100 -100

5x-88 = 0

5x -88 + 88 = 88

5x = 88

ria23 · Answer

I got 17.6
I'm not supposed to use mixed numbers, or decimal approximations of irrational numbers... Would this be the answer, or would I have to change it?

hartnn · Answer

isn't a fraction allowed?

5x =88
x= 88/5

ria23 · Answer

>~< Oh yea. 
xD Thank yhu both so much for yhur help~

ria23 · Answer

Would yhu mind helping me with one more?

hartnn · Answer

welcome ^_^ 
and sure, i'd be glad to :)

ria23 · Answer

Alright n_n 
I'll open up a new thread and tag yhu.
Thank yhu again! I really appreciate it~

solomonzelman · Answer

I was wondering, why not
yes. 

5x+12 = 100

5x = 100 -12

5x = 88

x = 88/5

lol