Answer
The answer can be seen in the image below.
Work Step by Step
For the first measure: $\frac{1}{4} + \frac{1}{4} + \frac{1}{8} + \frac{1}{8} = \frac{3}{4}$
For the second measure: $\frac{1}{4} + \frac{1}{4} + \frac{1}{4} = \frac{3}{4}$
For the third measure: $\frac{1}{4} + \frac{1}{8} + \frac{1}{8} + \frac{1}{8} + \frac{1}{8} = \frac{3}{4}$
For the fourth measure: $\frac{1}{4} + \frac{1}{4} + \frac{1}{8} + \frac{1}{8} = \frac{3}{4}$
When adding fractions with different denominators, all you have to do is convert them into fractions with the a common denominator then add and simplify. For example, in the first measure $\frac{1}{4}$ becomes $\frac{2}{8}$. If we add $\frac{2}{8} + \frac{2}{8} + \frac{1}{8} + \frac{1}{8} $, it equals $\frac{6}{8}$. The simplified form of $\frac{6}{8}$ is equal to $\frac{3}{4}$.