How do you solve #ln(9r+1)=ln(r^2+9)#?

1 Answer
Sep 3, 2016

Answer:

The Soln. is #r=8,1#.

Explanation:

Since, #ln# function is #1-1#,

#ln(9r+1)=ln(r^2+9)#

# rArr 9r+1=r^2+9, or, r^2-9r+8=0#

# rArr (r-8)(r-1)=0#

# rArr r=8, r=1#.

Both these roots satisfy the given eqn. Hence,

The Soln. is #r=8,1#.