5 * 8^4x = 376
x = 4 log 75.2/log 8
x = log 8/4 log 75.2
x = 4 log 8/log 75.2
x = log 75.2/4 log 8
Divide both sides by 5
8^(4x) = 376/5
Take the log of both sides
log 8^(4x) = log (376/5) = log (72.5) and we can write
(4x) log 8 = log (72.5) divide both sides by 4 log8
x = log (72.5) / [ 4 log (8) ]