Question

log2(x-1)+log2(x+1)=3 How do I work this problem out? Answer should be 3.

Answer 1

Is the 2 after the log the base or is it 2 multiplied by the quantity?

Answer 2

log base of 2, not mulitply

Answer 3

ok

Answer 4

when adding logs you can bring them together by multiplying there arguments.

\[\log_{2}[(x-1)*(x+1)]=3\]

\[(x-1)(x+1)=2^3\]

\[x^2-1=8\]

\[x=\pm3\]

Answer 5

thank you i appreciate your time. i will practice these questions after i get rest :P

Answer 6

yea no problem. =)