Упростите выражение: a) 7,3x + 4x; б) 3a - 5a; в) n - 4/5n; г) -5/7m + m; д) 2,1x + 4,5x - 1,9x; е) 7/4a + 8/11a - 4/11a; ж) -6a - a + 7; з) 9n – 5y - 4n + 7y; и) 3,6x + 5,1y - 2,9x - 4,

Решение:

• a) \(7,3x + 4x = (7,3 + 4)x = 11,3x\)
• б) \(3a - 5a = (3 - 5)a = -2a\)
• в) \(n - \frac{4}{5}n = 1n - \frac{4}{5}n = \frac{5}{5}n - \frac{4}{5}n = \frac{1}{5}n\)
• г) \(-\frac{5}{7}m + m = -\frac{5}{7}m + \frac{7}{7}m = \frac{2}{7}m\)
• д) \(2,1x + 4,5x - 1,9x = (2,1 + 4,5 - 1,9)x = 4,7x\)
• е) \(\frac{7}{4}a + \frac{8}{11}a - \frac{4}{11}a = \frac{7}{4}a + (\frac{8}{11} - \frac{4}{11})a = \frac{7}{4}a + \frac{4}{11}a = \frac{77}{44}a + \frac{16}{44}a = \frac{93}{44}a\)
• ж) \(-6a - a + 7 = -7a + 7\)
• з) \(9n - 5y - 4n + 7y = (9n - 4n) + (-5y + 7y) = 5n + 2y\)
• и) \(3,6x + 5,1y - 2,9x - 4 = (3,6x - 2,9x) + 5,1y - 4 = 0,7x + 5,1y - 4\)