Question

How does
log base 2 (x+1)(x+5)=4
turn into:
2^4= (x+1)(x-5) ?

Answer 1

thats how the log is defined

\[\large a^x = y \rightarrow x = \log_{a} y\]

Answer 2

log(base 2 ) (x +1)(x + 5) = 4
[log (x+1)(x+5)]/log 2 = 4
[log (x+1)(x+5)] = 4log2
[log (x+1)(x+5)] = log(2^4)
taking antilog on both sides,
(x+1)(x+5) = 2^4

Answer 3

@mitul why would you divide by log 2? can't you only do that with the quotient property? and i don't think we have learned antilogs yet...

Answer 4

dividing by log 2 is due to a property called change of base..
whenever we have log(base a)b, we can write as
log(base exponential)b/log(base exponential)a or simply ln(b)/ln(a).
ln means natural log.

Answer 5

And antilog is just the opposite property of log just as positive nullifies negative!!

Answer 6

Okay thank you....do you know of a loop method because we learned that in school but i don't quite understand it...?

Answer 7

i don't know the name but i just might be able to identify the method if u can show me wat is it??

Answer 8

this is what we learned for a simpler one and we are supposed to apply the same principal i think... thats what we learned in class