Question

see attachment

Answer 1

\[\log_b \frac{ x }{ y }=\log_bx-\log_by\]

Answer 2

log4 (4/y)=x
4^x = 4/y
ln4^x = ln(4/y)
xln4=ln(4/y)
x=(ln4)/(ln(4/y))
= ln(4-(4/y))