Answer:
Ok, suppose that we have two fractions with the same denominator but different numerator, let's write them as:
a/b and c/b
We can write these two as:
a*(1/b) and c*(1/b)
Now if we want to add these, we get:
a*(1/b) + c*(1/b)
Now we can take the common factor (1/b), and write the sum as:
(a + c)*(1/b)
now we can rewrite this as:
(a + c)/b
then we got:
a/b + c/b = (a + c)/b
We can directly compare the numerators because we can think on the same denominator as a common factor.
