log_4n 40sqrt3 = log_3n 45, solve for n
log(40sqrt(3))log(3n) =log(45)log(4n)
1.840620log(3n) = 1.653213log(3n) divide both sides by 1.6532131
1.11335996log(3n) =log(4n)
Solve for n:
(log(n) + log(4))/(log(n) + log(3)) = 1.11336
Simplify and substitute x = 1/(log(n) + log(3)).
(log(n) + log(4))/(log(n) + log(3)) = (log(4/3))/(log(3) + log(n)) + 1
= x log(4/3) + 1:
log(4/3) x + 1 = 1.11336
Subtract 1 from both sides:
log(4/3) x = 0.113359
Divide both sides by log(4/3):
x = 0.394043
Substitute back for x = 1/(log(n) + log(3)):
1/(log(n) + log(3)) = 0.394043
Take reciprocals of both sides:
log(n) + log(3) = 2.5378
Subtract log(3) from both sides:
log(n) = 1.43918
Cancel logarithms by taking exp of both sides:
n = 4.21725, n^3 =~75