3,3а + (а - 4) = 3,3а + а - 4 = 4,3а - 4
5,3b - (2b + 3) = 5,3b - 2b - 3 = 3,3b - 3
2c - (9 - 5,1c) = 2c - 9 + 5,1с = 7,1с - 9
4(х + у) + 5(2х - у) = 4х + 4у + 10х - 5у = 14х - у
- 3/4(1/3m + n) - 1/4(3m + n) = - 3/12m - 3/4n - 3/4m - 1/4n = (- 3/12m - 3/4m) + (- 3/4n - 1/4n) = (- 3/12m - 9/12m) + (- 4/4n) = - 12/12m - 4/4n = - m - n