Tìm, biết

Bài 9: Tìm, biết:

1/ 2(2x + 3) = 4 

2/ (8x -3)3x - 12x.2x + 5 = 12

3/ 2x² + 2x(x - 1) = 5(x + 1)

4/ 6x(5x +3 ) + 3x(1 - 10x) = 1

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

6/ (3x -3) (5 - 21x) + (7x +4) (9x - 5) = 44