You are here:

- Home
- Science
- Math for Kids
- Algebra
- algebra 2

Advertisement

Please help an thank you so much /loga. (3x+5)-loga. (X-5)=loga 8

As I read the problem, what I see is log(3x+5) - log(x-5) = log(8)

where all the log's are base a.

Note that when the difference of logs is taken, it is the same as dividing the numbers.

This means the problem is log((3x+5)/(x-5)) = log(8), all log's in base A.

It is known that A^log(x) = x when the log is in base A.

This can be done to both sides, so we have (3x+5)/(x-5) = 8.

Multiplying both sides by (x-5) gives 3x+5 = 8x-40.

Adding -8x-5 to both sides gives -5x = = -45.

Dividing both sides by -5 gives x = 9.

Checking this gives log(32) - log(4) = log(8), all log's base a.

If we take the base a as 2, we get, since 32=2^5, 4=2^2, and 8=2^3, 5 - 2 = 3.

From this, the answer checks out.

If we don't worry about what a is, we can take convert log(32) - log(4) = log(32/4) = log(8).

Algebra

Answers by Expert:

Any algebraic question you've got. That includes question that are linear, quadratic, exponential, etc.

I have solved story problems, linear equations, parabolic equations.
I have also solved some 3rd order equations and equations with multiple variables.
**Publications**

Documents at Boeing in assistance on the manufacturiing floor.**Education/Credentials**

MS at math OSU in mathematics at OSU, 1986.
BS at OSU in mathematical sciences (math, statistics, computer science), 1984.
**Awards and Honors**

Both my BS and MS degrees were given with honors.
**Past/Present Clients**

Students in a wide variety of areas since the 80's; over 1,000 of them have been in algebra.