Basic College Mathematics (10th Edition)

There is no minuend, so the parenthesis are being used to indicate a negative number. Add and subtract from left to right. $\frac{1}{2}-\frac{2}{3}+(-\frac{5}{6})\longrightarrow$ use least common multiple to create a common denominator = $\frac{1\times3}{2\times3}-\frac{2\times2}{3\times2}+(-\frac{5}{6})\longrightarrow$ simplify = $\frac{3}{6}-\frac{4}{6}+(-\frac{5}{6})\longrightarrow$ solve the first subtraction = $-\frac{1}{6}+(-\frac{5}{6})\longrightarrow$ solve the addition = $-\frac{6}{6}\longrightarrow$ simplify = $-1$