How do you solve log (3x+1) = 1 + log (2x-1)log(3x+1)=1+log(2x1)?

1 Answer
Dec 23, 2015

The explanation is given below.

Explanation:

log(3x+1)=1+log(2x-1)log(3x+1)=1+log(2x1)
log(3x+1)=log(10)+log(2x-1)log(3x+1)=log(10)+log(2x1) since log(10)=1log(10)=1
log(3x+1)=log(10(2x-1))log(3x+1)=log(10(2x1)) Product rule of logarithms
3x+1 = 10(2x-1)3x+1=10(2x1) if logA = log B then A= B
3x+1 = 20x-103x+1=20x10 distributive law

Now we have to solve for x using inverse operaitions to isolate x.

3x+1 + 10 = 20x-10+103x+1+10=20x10+10

Adding 10 on both sides would remove 1010 from the right side of the equation

3x+11=20x3x+11=20x
3x+11-3x=20x-3x3x+113x=20x3x

Subtracting 3x3x on both sides would isolate the term containing xx to one side of the equation.

11=17x11=17x

Dividing both sides by 17 we get

11/17=(17x)/171117=17x17

11/17 = x1117=x

x=11/17x=1117 Answer