Add and simplify

Explanation

Consider the problem \(\frac35 + \frac15\).  When we write it in words, it is apparent that we are adding similar objects.

three-fifths + one-fifths

Because the denominators of  \(\frac35\) and \(\frac15\) are the same, we say that they have a common denominator.  Since the fractions have a common denominator, we can add them.  The following figure explains the addition process.

three-fifths

+

one-fifths

=

four-fifths