If 1 + log₁₀a = 2log₁₀b, then express a by b

Let us write by calculating, find its base if logarithm of 625 is 4

Let us write by calculating, find its base if logarithm 5832 is 6

If 3 + log₁₀x = 2log₁₀y, then express x by y

Let us evaluate:

log₂[log₂{log₃ (log₃27³)}]