Solve an equation containing a log?

How do you solve this equation?

log(3x+1)=2

2013-08-19T13:54:27Z

That is how the equation is listed, so I would say its safe to assume its log base 10.

Raymond2013-08-19T13:53:28Z

Favorite Answer

Find the "antilog"

If the log is in base 10, then the "antilog" of 2 is 10^2 (equal to 100)

the antilog of a log is simply the "argument" of the log.

(if the base is 10)
10^(log(3x+1)) = 3x+1

Therefore, by taking the antilog on both sides, you would get
3x + 1 = 10^2

(if the base is not 10, then simply use the correct base):

3x + 1 = (base)^2

Ed2013-08-19T20:53:33Z

Assuming you mean log to the base of 10,

3x + 1 = 10^2 = 100 so 3x = 99 so x = 33

lenpol72013-08-19T20:56:30Z

log(3x+1)=2

Antilog

3x + 1 = 10^2
3x + 1 = 100
3x = 99
x = 33

Professor Of Wumbology2013-08-19T20:56:12Z

log(b) = a just means 10^a = b.

"log(3x+1) = 2" turns into "10^2 = 3x+1"

10^2 = 3x + 1

100 = 3x + 1

99 = 3x

x = 33

Chris2013-08-19T20:56:02Z

antilog 2 = 100

Hence log 100 = 2
Hence 3x + 1 = 100
Hence 100 - 1 = 99 = 3x
Therefore x = 99/3 = 33

Show more answers (1)