SOLUTION: Hi. How would I solve the problem log2 (x^2-9)=4 Would I factor out the (x^3-9) to make its (x+3) (x-3) Then go from there?

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: Hi. How would I solve the problem log2 (x^2-9)=4 Would I factor out the (x^3-9) to make its (x+3) (x-3) Then go from there?      Log On


   

Question 452885: Hi. How would I solve the problem log2 (x^2-9)=4 Would I factor out the (x^3-9) to make its (x+3) (x-3) Then go from there?
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
log%282%2C+x%5E2+-+9%29+=+4
<==> 2%5E4+=+x%5E2+-+9
==> 25+=+x%5E2
==> x = -5, 5.
Both values satisfy the original equation, and so are the final answers.