college math

how do you do the problem log base 3 of 20 -log base 3 of 6 - log base 3 of 30

=log base 3 of (20/6 divided by 30)

=log base 3 of (20/6 * 1/30)

=log base 3 of (1/9)

=log base 3 of (3 ^-2)

=-2 log base 3 of 3

= -2 *1
= -2

I suggest that you work through this web site
http://www.mathsisfun.com/algebra/logarithms.html