How do you solve log_6(b^2 + 2) + log_6 2 = 2log6(b2+2)+log62=2?

1 Answer
Jul 30, 2015

I found: b=+-4b=±4

Explanation:

You can start using a property of logs:
logx+logy=logxylogx+logy=logxy
so you get:
log_6[2(b^2+2)]=2log6[2(b2+2)]=2
using the definition of log:
log_ax=b -> x=a^blogax=bx=ab you get:
2(b^2+2)=6^2=362(b2+2)=62=36
b^2+2=36/2=18b2+2=362=18
b^2=18-2=16b2=182=16
so that b=+-sqrt(16)=+-4b=±16=±4