Bạn tham khảo nhé
a) 3(2x - 1) - 2(1 - x) = x + 9
<=> 6x - 3 - (2 - 2x) = x + 9
<=> 6x - 3 - 2 + 2x - x = 9
<=> 7x = 14
<=> x = 2
Vậy x = 2
b) -3(2x - 1) - 2(1 - x) = x + 9(1 - x)
<=> -6x + 3 - (2 - 2x) = x + 9 - 9x
<=> -6x + 3 - 2 + 2x - x + 9x = 9
<=> 4x = 8
<=> x = 2
Vậy x = 2
c) (1 - x)(2x - 1) - 2(2 - x)(2 + x) = x + 9
<=> 2x - 1 - 2x² + x - (4 - 2x)(2 + x) - x = 9
<=> 2x - 1 - 2x² + x - (8 + 4x - 4x - 2x²) - x = 9
<=> 2x - 1 - 2x² + x - 8 - 4x + 4x + 2x² - x = 9
<=> 2x = 18
<=> x = 9
Vậy x = 9
