Chapter 4 - Section 4.6 - Complex Fractions and Review of Order of Operations - Exercise Set - Page 285: 46

$-\frac{5}{16}$

$(-\frac{1}{2})^{2}-(\frac{3}{4})^{2}$ $=(-\frac{1}{2})(-\frac{1}{2})-(\frac{3}{4})(\frac{3}{4})$ $=--(\frac{1}{2}\times\frac{1}{2})-(\frac{3}{4}\times\frac{3}{4})$ $=(\frac{1}{2}\times\frac{1}{2})-(\frac{3}{4}\times\frac{3}{4})$ $=\frac{1}{4}-\frac{9}{16}$ $=\frac{4}{16}-\frac{9}{16}$ $=-\frac{5}{16}$