Chapter 5.1, Problem 15P

a. Write an expression that uses both multiplication and addition (or subtraction) to describe the total fraction of Figure 5.7 that is shaded. (For example, $\frac{5}{7}.\frac{2}{9}+\frac{1}{3}$ is an expression that uses both multiplication and addition) Explain your reasoning. Then determine what fraction of the figure is shaded (in simplest form). You may assume that lengths appearing to be equal really are equal.

 

  Figure 5.7 What fraction is shaded?

b. Draw a figure in which you shade $\frac{1}{4}.\frac{1}{3}+\frac{3}{5}.\frac{1}{3}$ of the figure. Explain your reasoning, then determine what fraction of the figure is shaded (in simplest form).