SOLUTION: Please help!! This equation is on a work sheet that I need to solve: log4 (X^2 - 4) - log4 (X + 2) = 2 (note : log4 is log base 4, I can't make subscripts)

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: Please help!! This equation is on a work sheet that I need to solve: log4 (X^2 - 4) - log4 (X + 2) = 2 (note : log4 is log base 4, I can't make subscripts)       Log On


   

Question 70986: Please help!! This equation is on a work sheet that I need to solve:

log4 (X^2 - 4) - log4 (X + 2) = 2
(note : log4 is log base 4, I can't make subscripts)
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
log%284%2Cx%5E2-4%29+-+log%284%2Cx%2B2%29+=+2
Note the rule that
log%28a%29+-+log%28b%29+=+log%28a%2Fb%29
log%284%2C%28x%5E2-4%29%2F%28x%2B2%29%29+=+2
log%284%2C%28x%2B2%29%28x-2%29%2F%28x%2B2%29%29+=+2
log%284%2Cx-2%29+=+2
4%5E2+=+x-2
16+=+x-2
x+=+18 answer
check the answer
log%284%2Cx%5E2-4%29+-+log%284%2Cx%2B2%29+=+2
log%284%2C18%5E2-4%29+-+log%284%2C18%2B2%29+=+2
log%284%2C320%29+-+log%284%2C20%29+=+2
log%284%2C320%2F20%29+=+2
log%284%2C16%29+=+2
4%5E2+=+16
16+=+16
OK