Question

log_4^2(x)-5log_4(x)-4=0

Answer 1

$log_{4}^{2}x - 5log_{4}x - 4 = 0$
$t = log_{4}x$
t^2 - 5t - 4 = 0
t = (5 +- √(25 + 16)) / 2 = (5 +- √41)/2

$log_{4}x = t$
x = 4 ^ t
x = 4 ^ ((5 +-√41) / 2) = 2 ^ (5 +- √41)