Вариант 1. Задание 2. Выполните действия: a) 25 – (-11); б) -15,8 – (-7,9); в) -3\(\frac{5}{6}\)-4\(\frac{1}{3}\); г) 5\(\frac{7}{20}\) - 6\(\frac{23}{30}\).

a) 25 - (-11) = 25 + 11 = 36
б) -15,8 - (-7,9) = -15,8 + 7,9 = -7,9
в) -3\(\frac{5}{6}\)-4\(\frac{1}{3}\) = -\(\frac{3*6+5}{6}\) - \(\frac{4*3+1}{3}\) = -\(\frac{23}{6}\) - \(\frac{13}{3}\) = \(\frac{-23 - 13*2}{6}\) = \(\frac{-23 - 26}{6}\) = \(\frac{-49}{6}\) = -8\(\frac{1}{6}\)
г) 5\(\frac{7}{20}\) - 6\(\frac{23}{30}\) = \(\frac{5*20 + 7}{20}\) - \(\frac{6*30 + 23}{30}\) = \(\frac{107}{20}\) - \(\frac{203}{30}\) = \(\frac{107*3 - 203*2}{60}\) = \(\frac{321 - 406}{60}\) = \(\frac{-85}{60}\) = -\(\frac{17}{12}\) = -1\(\frac{5}{12}\)