179. Найдите значение выражения -7,9 – х, если: 1) x = -3,4; 2) x = 2,7; 3) x = -5 5/12; 4) x = 4 1/3.

179. Решение: 1) \(-7.9 - (-3.4) = -7.9 + 3.4 = -4.5\) 2) \(-7.9 - 2.7 = -10.6\) 3) \(-7.9 - (-5\frac{5}{12}) = -7.9 + 5\frac{5}{12} = -7.9 + \frac{65}{12} = -7\frac{9}{10} + 5\frac{5}{12} = -\frac{79}{10} + \frac{65}{12} = -\frac{474}{60} + \frac{325}{60} = -\frac{149}{60} = -2\frac{29}{60}\) 4) \(-7.9 - 4\frac{1}{3} = -7.9 - \frac{13}{3} = -7\frac{9}{10} - 4\frac{1}{3} = -\frac{79}{10} - \frac{13}{3} = -\frac{237}{30} - \frac{130}{30} = -\frac{367}{30} = -12\frac{7}{30}\)