SOLUTION: log subscript 8 square root 80 - log subscript 8 square root 5

Algebra.Com
Question 196625: log subscript 8 square root 80 - log subscript 8 square root 5
Found 2 solutions by scott8148, jim_thompson5910:
Answer by scott8148(6628)   (Show Source): You can put this solution on YOUR website!
subtracting logs means dividing their arguments

log subscript 8 [(square root 80)/(square root 5)]

log subscript 8 [square root (80/5)]

log subscript 8 [square root (16)]

log subscript 8 (4)

4 is 2^2 and 8 is 2^3 ___ so 4 = 8^(2/3)

log subscript 8 (4) = 2/3

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
... Start with the given expression.


... Combine the logs using the identity .


... Factor 80 into 16*5.


... Break up the square root.


... Take the square root of 16 to get 4.


... Reduce


... Use the change of base formula



Remember the change of base formula is



... Rewrite each argument as a power of 2


... Pull down the exponents using the identity


... Cancel out the common terms.



So

RELATED QUESTIONS

5 log subscript 8,... (answered by tommyt3rd)
If log (subscript b)M=x and log (subscript b)N=y, express the following in terms of x and (answered by user_dude2008,stanbon)
log(subscript 3) 8 * log(subscript 8)... (answered by stanbon,user_dude2008)
Log{subscript 8}x + log{subscript 8}(x-2)=2 (answered by lwsshak3)
log (subscript 2) (x^2+8) = log (subscript 2)x +log (subscript... (answered by chiefman)
Evaluate: log (subscript 8)(1/16)... (answered by jim_thompson5910)
Express as a sum, difference, or multiple of logarithms. log(subscript 2)(square root... (answered by jim_thompson5910,josmiceli)
Express as a logarithm of a single number of expression log(subscript 2)5 + log... (answered by jim_thompson5910,solver91311)
Find domain: f(x)= log(x^2-7x+6) f(x)= ln(log(2x+4)) f(x)= square root of... (answered by edjones)