# Algebra 2

how do not understand how to do this

Log X + Lob (X-3) = 1

I know I do this

Log X(X-3)=1

then I do this

Log X^(2) - 3X = 1

then I do this

2 Log (X-3X) = 1

then

2 Log (-2X) = 1

then

(2 Log (-2X) = 1)(1/2)

Log (-2X) = 1/2

then

(Log (-2X) = 1/2)(-1/2)

Log X = (-1/4)

then

by def

10^ (-1/4) = X

I get something under one and calculator tells me I can't do that I think I'm doing something wrong what do I do?

1. 👍 0
2. 👎 0
3. 👁 234
1. Log X + Lob (X-3) = 1

I know I do this

Log X(X-3)=1

Then take the antilog of each side
x(x-3)=0
Now solve it.

1. 👍 0
2. 👎 0
2. what exactly is antilog?

3. your notation at Log X^(2) - 3X = 1 is sloppy

say: Log (X^(2) - 3X) = 1

your next line of 2 Log (X-3X) = 1
is WRONG

from Log (X^(2) - 3X) = 1 by definition of logs
x^2 - 3x = 10^1
x^2 - 3x - 10 = 0
(x-5)(x+2) = 0
x = 5 or x = -2

but in logx, x > 0, so

x = 5

check: if x=5
LS = log5 + log2
= log(5x2)
= log 10
= 1
= RS

1. 👍 0
2. 👎 0
posted by Reiny

1. 👍 0
2. 👎 0
5. ok um so
Log (X^(2) - 3X) = 1
x^2 - 3x = 10^1

what allows you to put in the value ten and get ride of the log on the other side? What if the value wasn't one would u just do 10^X?

x^2 - 3x - 10 = 0
(x-5)(x+2) = 0
x = 5 or x = -2

6. NO, it is x=5
I verified it

Here is yours:
if x=3
LS= log3 + log1
= log(3x1)
= log 3 which is not equal to the RS of 1

1. 👍 0
2. 👎 0
posted by Reiny
7. LOGb<?sub> a = c <----> bc = a

e.g.
log2 8 = 3 <---> 23 = 8

1. 👍 0
2. 👎 0
posted by Reiny
8. let's try that again

LOGb a = c <----> bc = a

e.g.
log2 8 = 3 <---> 23 = 8

1. 👍 0
2. 👎 0
posted by Reiny
9. ok um so
Log (X^(2) - 3X) = 1
x^2 - 3x = 10^1

what allows you to put in the value ten and get ride of the log on the other side? What if the value wasn't one would u just do 10^X?

x^2 - 3x - 10 = 0
(x-5)(x+2) = 0
x = 5 or x = -2

## Similar Questions

1. ### math

Logarithm!!! Select all of the following that are true statements: (a) log(2x) = log(2) + log(x) (b) log(3x) = 3 log(x) (c) log(12y) = 2 log(2) + log(3y) (d) log(5y) = log(20y) – log(4) (e) log(x) = log(5x) – log(5) (f) ln(25)

asked by Simon on April 16, 2010
2. ### precalc

I don't understand how to do these w/o calc. I tried to write it in a way that will make someone understand how to read it. Hope I typed it clear enough.Thanks so much for the help anyone! How to find the exact value of logarithm:

asked by Katie on November 12, 2015
3. ### Mathematics

Prove that log a, log ar, log ar^2 is an a.p. Is the following below correct? Log ar^2 - Log ar= Log ar - Log a hence applying laws of logarithm Log(ar^2/ar) = log(ar/a) Log and log cancels out and then cross-multiply hence a^2r^2

asked by Anonymous on July 15, 2009
4. ### Algebra 2

solve for x: 3^2x+3=7^x+1 I did 2x+3=log0f3(7)+ logof3(7) (2-log of 3(7))x=log of 3(7)-3 x=log of 3 (7)+log of 3 (3^-3)/log 0f 3 (3^2)-log of 3 (7) x=log of 3 (7-1/3^3)/log of 3(9/7) log of 3(7/27)/log of 3(9/7) answer log of

asked by sara on March 3, 2019
5. ### chemistry

Please, can someone help? Evaluate log 1. This is my work up until I have gotten stuck: log 1 1=10^x I can't find a common base for 1 and 10^x. Wow, my apologies, this is algebra, not chemistry. but actually I think they use it in

asked by Darcy on April 10, 2007
6. ### math

write as a single logarithm: -2logbase3(1/x)+(1/3)logbase3(square root of x) please show the steps to solving this. thanx. remember that 1 log (AxB) = log A + Log B (same base) 2 log (A/B) = log A - log B 3 log A^n = n log A use

asked by michelle on February 25, 2007
7. ### Algebra 2 once more

I have more answers that I would like checked. Also, there is one that I'm really confused about. I appreciate any help. :) Rewrite as the log of a single number. 1) 8 ln 2 = ln(2^8) 2) log 42 - log 6 = log 36 (I think this one

asked by Lindsay on May 23, 2007
8. ### trigonometry repost .

This is an outline that i have to use to find the solution of the question. It involves logarithms and half-angle formulas.I have worked though it but got stuck on some parts. I'd like if you look over my work. solve the triangle

asked by Anon on March 1, 2011
9. ### pre-cal

Use logarithms to solve log 8 / log x < 1. I understand that there are 2 cases: when x is negative or positive. I don't understand how it affects the answer though.

asked by mike on May 24, 2010
10. ### domain

How do you find the domain of log(x^2-4)? and how about this one? e^(3x+4)? Please help me! Well kristie, you might recognize log(x^2-4) = log((x-2)(x+2)) and then use a property of logs to see it as a sum, i.e.,

asked by kristie on July 17, 2006

More Similar Questions