Question 448980
Determine the solution to the following equation:
 log(a) + log(a + 12) = 2 log(a + 4).
 log(a(a+12)) = log ((a+4)^2)
therefore
a(a+12) = (a+4)^2
:
a^2 + 12a = a^2 + 8a + 16
:
a^2 - a^2 + 12a - 8a = 16
4a = 16
a = {{{16/4}}}
a = 4
:
Check: 
log(4) + log(4 + 12) = 2 log(4 + 4).
log(4) + log(16) = 2 log(8).
log(4) + log(16) = log(8^2).
log(4*16) = log(64)