Math of the following functions

Question

y= 7x - ln(4x³)

y= log₇(5x)

Answer 1

as to the 2nd problem

y = log₇(5x)

means the same as

7^y = 5x

rewritten in exponential form

in general log_ba = c means b^c= a, the log is an exponent

divide by 5

x = 7^y/5