Chapter R - Review of Basic Concepts - R.2 Real Numbers and Their Properties - R.2 Exercises - Page 20: 31

$-\frac{1}{4}$

$$(-\frac{2}{9}-\frac{1}{4})-[-\frac{5}{18}-(-\frac{1}{2})]$$ $$(-\frac{8}{36}-\frac{9}{36})-[-\frac{10}{36}-(-\frac{18}{36})]$$ $$(-\frac{17}{36}-[-\frac{10}{36}-(-\frac{18}{36})]$$ $$-\frac{17}{36}-[-\frac{8}{36}]$$ $$-\frac{17}{36}+\frac{8}{36}$$ $$-\frac{9}{36}$$ $$-\frac{1}{4}$$