1. а) 5a*2b - 15b*2 = 10b * (a - 3)
б) 18a*4 + 6a*2 = 12a * (6 + 1) = 12a * 7
2. 30 + 5(3x - 1) = 35x - 25
30 + 15x - 5 = 35x - 25
20x = 50
x = 2,5
3. 2а(а - b + с) + 2b(а – b – с) – 2с(а + b – с) = 2a² - 2ab + 2ac + 2ab - 2b² - 2bc - 2ac + 2bc + 2c² = 2a² - 2b² + 2c²
1. а) 5a*2b - 15b*2 = 10b * (a - 3)
б) 18a*4 + 6a*2 = 12a * (6 + 1) = 12a * 7
2. 30 + 5(3x - 1) = 35x - 25
30 + 15x - 5 = 35x - 25
20x = 50
x = 2,5
3. 2а(а - b + с) + 2b(а – b – с) – 2с(а + b – с) = 2a² - 2ab + 2ac + 2ab - 2b² - 2bc - 2ac + 2bc + 2c² = 2a² - 2b² + 2c²