# Math Help - Logs solving for x

1. ## Logs solving for x

Solving for x:

log4 (x - 10) + log4 (x + 10) = 4

2. Originally Posted by tmac11522
Solving for x:

log4 (x - 10) + log4 (x + 10) = 4
$log_a(m) + log_a(n) = log_a{(mn)}$

$log_4{((x+10)(x-10))} = 4$
$log_4{(x^2-100)} = 4$
$x^2-100=4^4$
$x^2-356=0$
$x = 2\sqrt{89}$