SOLUTION: Solve for x: log base 3 (x+4)+log base 3 (x-2)=3

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Solve for x: log base 3 (x+4)+log base 3 (x-2)=3      Log On


   

Question 849389: Solve for x: log base 3 (x+4)+log base 3 (x-2)=3
Answer by LinnW(1048) About Me  (Show Source):
You can put this solution on YOUR website!
log3%28x%2B4%29%2Blog3%28x-2%29=3
since log3(3^3) = 3
log3%28x%2B4%29%2Blog3%28x-2%29=log3%283%5E3%29
log3%28%28x%2B4%29%2A%28x-2%29%29=log3%2827%29
log3%28x%5E2%2B2x-8%29=log3%2827%29
x%5E2%2B2x-8=27
add -27 to each side
x%5E2%2B2x-35=0
%28x%2B7%29%2A%28x-5%29=0
x = -7 or x = 5
x = -7 does not work in the original
equation so x = 5 .