1.
1) (2a² - a + 3) + (3a² + a - 7) = 2a² - a + 3 + 3a² + a - 7 = 5a² - 4
2) (3a - 4ab + 2) - (11a - 14ab) = 3a - 4ab + 2 - 11a + 14ab = 10ab - 8a + 2
3) 3y² *(y³ + 1) = 3y^5 + 3y²
4) 2a * (a - 3) - 2 * (a² - 4a) = 2a² - 6a - 2a² + 8a = 2a
2.
а)30 + 5 * (3x - 1) = 35x - 25
30 + 15x - 5 = 35x - 25
15x - 35x = 5 - 25 - 30
-20x = -50
x = -50/-20 = 2,5
3.
9a + 9b = 9(a + b)
7ab - 7ax = 7a(b - x)
18a³ + 6a² = 6a²(3a + 1)