2. Вычислите: a) |-3,21 + 1-1,91 – 12,251; б) 1-\frac{17}{48}: 1-2\frac{5}{6}.

2. Вычислите: а) |-3,21 + 1-1,91 – 12,251| = |-3,21 + 1,91 - 12,25| = |-13,55 + 1,91| = |-11,64| = **11,64** б) $1-\frac{17}{48}: 1-2\frac{5}{6} = 1-\frac{17}{48} : \frac{11}{6} = 1 - \frac{17}{48} \cdot \frac{6}{11} = 1 - \frac{17}{8 \cdot 6} \cdot \frac{6}{11} = 1 - \frac{17}{88} = \frac{88-17}{88} = \frac{71}{88}$ = **\frac{71}{88}**