Question

Solve logarithm Equation: log2 (12b - 21) - log2 (b^2 - 3)=2

Answer 1

Hn, well you should use the rule to answer this..
`log_a(n)-log_a(m)=log_a ((n)/(m) )`
Sorry if this doesn't seem to help, but here is the explanation:

`log_2 ((12b-21)/(b^2-3) )=2`

`(12b-21)/(b^2-3) =4`

`12b-21=4(b^4-3)`

`0=4b^2-12b-12+21`

`0=4b^2-12b+9`

`0=4b^2-6b-6b+9`

`0=2b(2b-3)-3(2b-3)`

`0=(2b-3)(2b-3)`

`b= (3)/(2)`
Hn, so from this information we can determine that this solution does not work. And so forth your solution set shall indeed be: {x= 0}

I wish you good luck on your homework and hopefully I was somewhat beneficial to your needs.

Best regards~ Sans