How do you simplify ln 3 − 2 ln 9 + ln 18 ?

1 Answer
Sep 1, 2015

ln 3 - 2 ln 9 + ln 18 = ln (2/3) = ln 2 - ln 3

Explanation:

Use:color(white)(XX)ln a + ln b = ln (ab)

and:color(white)(XX)ln a - ln b = ln (a/b)

to simplify:

ln 3 - 2 ln 9 + ln 18

=ln 3 + ln 18 - ln 9^2

=ln (3*18) - ln 81

=ln 54 - ln 81

=ln (54/81)

=ln (2/3)

=ln 2 - ln 3