Giải phương trình: 2x - (3 - 5x) = 4(x + 3)

1) 2x - (3 - 5x) = 4(x + 3)

2x - 3 + 5x = 4x + 12

3x = 15

x = 5

2) 5(2x - 3) - 4(5x - 7) = 19 - 2(x + 11)

20x - 15 - 20x + 28 = 19 - 2x - 22

2x = -16

x = - 8

3) 5x - 4(6 - x)(x + 3) = (4 - 2x)(3 - 2x) + 2

=> 5x - 24x - 72 + 4x² + 12x = 12 - 8x - 6x + 4x² + 2

=> 7x = 86

=> x = 86/7

4) (x - 1)³ - (3x + 2)(- 12) = (x² + 1)(x - 2) - x²

=> x³ - 3x² + 3x -1 + 36x + 24 = x³ - 2x² + x - 2 - x²

=> 38x = - 25

=> x = - 25/38