
In order
to do this follow the following steps:
 First find
the least common multiple of the denominators and make it the denominator
of each fraction.
 Next,
in order to find each of the new numerators, divide that number by the
denominator of a fraction and multiply it by the numerator.
 Finally,
add the numerators and enter the same denominator.
 Simplify
if possible.
In
this window you can see the process step by step by clicking on
the blue triangle.
When you click on Init other fractions will appear. Try to do it
several times.

