39 = (1 and 3/10) b
Let's change that ugly mixed number to a fraction
so that we can work with it.
(1 and 3/10) = (10/10 and 3/10) = 13/10
Now the equation says 39 = 13/10 b
We could multiple
each side by 10: 390 = 13 b
Divide each side by 13: 390 / 13 = 30 = b
Whenever you're trying to solve any equation, the whole idea is:
-- Do whatever you need to do in order to get the variable all alone
on one side of the equation and everything else on the other side.
-- You can do anything you want to do on either side of the equation,
BUT ...
-- whatever you do to one side, you must IMMEDIATELY do the same thing
to the other side.
