Answer: y = 36
Step-by-step explanation:
This is question on logarithm, so it is logarithmic equation.
Log4(y - 9) + log4 3 = log4 81
Now remembered that in logarithm, it is the opposite of the indices. The addition in log. means multiplication. So, log 4(y -9) + log 4 3 = log4{(y - 9)× 3}
So, log4{(y - 9) × 3 = log4 81
Now since log 4 is common, divide everything by log 4 leave the equation
3( y - 9 ) = 81
3y - 27. = 81
3y = 81 + 27
3y = 108
y = 108/3
y = 36.
