Вариант 2. Задание 2. Выполните действия: a) 17 – (-12); б) -7,4 – (-2,7); в)-1\(\frac{7}{8}\)-2\(\frac{1}{4}\); г) 3\(\frac{4}{15}\) - 4\(\frac{17}{20}\).

a) 17 - (-12) = 17 + 12 = 29
б) -7,4 - (-2,7) = -7,4 + 2,7 = -4,7
в) -1\(\frac{7}{8}\)-2\(\frac{1}{4}\) = -\(\frac{1*8+7}{8}\) - \(\frac{2*4+1}{4}\) = -\(\frac{15}{8}\) - \(\frac{9}{4}\) = \(\frac{-15 - 9*2}{8}\) = \(\frac{-15 - 18}{8}\) = \(\frac{-33}{8}\) = -4\(\frac{1}{8}\)
г) 3\(\frac{4}{15}\) - 4\(\frac{17}{20}\) = \(\frac{3*15 + 4}{15}\) - \(\frac{4*20 + 17}{20}\) = \(\frac{49}{15}\) - \(\frac{97}{20}\) = \(\frac{49*4 - 97*3}{60}\) = \(\frac{196 - 291}{60}\) = \(\frac{-95}{60}\) = -\(\frac{19}{12}\) = -1\(\frac{7}{12}\)