SOLUTION: how to express the following as a single log? 1. log7+ log4- log2= 2. 2log(ab)- 3log a+ 2= 3. log (X2 - 1) - LOG (X+1)

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: how to express the following as a single log? 1. log7+ log4- log2= 2. 2log(ab)- 3log a+ 2= 3. log (X2 - 1) - LOG (X+1)      Log On


   



Question 295270: how to express the following as a single log?
1. log7+ log4- log2=
2. 2log(ab)- 3log a+ 2=
3. log (X2 - 1) - LOG (X+1)

Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Remember:
log a - log b = log a/b
log a + log b = log ab
alogb = log b^a
.
1. log7+ log4- log2=
log(7*4) - log 2
log 28 - log 2
log 28/2
log 14
.
2. 2log(ab)- 3log a+ 2=
log (ab)^2 - log a^3 + 2
log (a^2b^2) - log a^3 + 2
log (a^2b^2)/a^3 + 2
log (b^2/a) + 2
.
3. log (X2 - 1) - LOG (X+1)
log (x^2-1)/(x+1)
factoring the numerator:
log (x-1)(x+1)/(x+1)
log (x-1)