Verified answer

a) - 0,5(3x - 4)+ 15x = 4(1,5x + 1) + 3

- 1,5x + 2 + 15x = 6x + 4 + 3

-1,5x + 15x - 6x = 4 + 3 - 2

7,5x = 5

x = 2/3

б) (2x - 3)(2x + 3) - x² = 12x - 69 + 3x²

4x² - 9 - x² = 12x - 69 + 3x²

4x² - x² - 12x - 3x² = 9 - 69

- 12x = - 60

x = 5