2. Найдите значение выражения: a)-46+27+(-30)+(-54) + 33; б)\frac{7}{12}⋅2\frac{3}{4}⋅(-\frac{12}{7}); в) 5,4⋅(-\frac{2}{11})-\frac{9}{11}⋅5,4.

а) \[ -46 + 27 + (-30) + (-54) + 33 = -46 + 27 - 30 - 54 + 33 = -19 - 30 - 54 + 33 = -49 - 54 + 33 = -103 + 33 = -70 \]

б) \[ \frac{7}{12} \cdot 2\frac{3}{4} \cdot \left(-\frac{12}{7}\right) = \frac{7}{12} \cdot \frac{11}{4} \cdot \left(-\frac{12}{7}\right) = \frac{7 \cdot 11 \cdot (-12)}{12 \cdot 4 \cdot 7} = -\frac{11}{4} = -2.75 \]

в) \[ 5.4 \cdot \left(-\frac{2}{11}\right) - \frac{9}{11} \cdot 5.4 = 5.4 \cdot \left(-\frac{2}{11} - \frac{9}{11}\right) = 5.4 \cdot \left(-\frac{11}{11}\right) = 5.4 \cdot (-1) = -5.4 \]