5.85 Приведите подобные слагаемые: a) 3m + 2m + 4m; 1 б) a + 1/3 a - 1/6 a; 2 в) 0,9b - 1,3b + 0,7b; 1 г) m - 1/4 m - 1/3 m; 12 д) х - 0,2x - 0,7x; e) c – 0,8c – 1/5 c – 1/2

a) \(3m + 2m + 4m = (3 + 2 + 4)m = 9m\)

б) \(\frac{1}{2}a + \frac{1}{3}a - \frac{1}{6}a = (\frac{1}{2} + \frac{1}{3} - \frac{1}{6})a = (\frac{3}{6} + \frac{2}{6} - \frac{1}{6})a = \frac{4}{6}a = \frac{2}{3}a\)

в) \(0.9b - 1.3b + 0.7b = (0.9 - 1.3 + 0.7)b = (1.6 - 1.3)b = 0.3b\)

г) \(\frac{1}{12}m - \frac{1}{4}m - \frac{1}{3}m = (\frac{1}{12} - \frac{1}{4} - \frac{1}{3})m = (\frac{1}{12} - \frac{3}{12} - \frac{4}{12})m = (\frac{1 - 3 - 4}{12})m = \frac{-6}{12}m = -\frac{1}{2}m\)

д) \(x - 0.2x - 0.7x = (1 - 0.2 - 0.7)x = (1 - 0.9)x = 0.1x\)

е) \(c - 0.8c - \frac{1}{5}c - \frac{1}{2} = c - 0.8c - 0.2c - \frac{1}{2} = (1 - 0.8 - 0.2)c - \frac{1}{2} = (1 - 1)c - \frac{1}{2} = 0c - \frac{1}{2} = -\frac{1}{2}\)

Ответ:

• a) \(9m\)
• б) \(\frac{2}{3}a\)
• в) \(0.3b\)
• г) \(-\frac{1}{2}m\)
• д) \(0.1x\)
• е) \(-\frac{1}{2}\)