a) 12 - 2(x + 1) = 3x - 5

=> 12 - 2x - 2 = 3x - 5

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

=> -5x = -15

=> x = 3

Vậy...........

b) \(\dfrac{2}{7}\left(3x+1\right)=2+\dfrac{6}{7}x\)

=> \(\dfrac{6}{7}x+\dfrac{2}{7}=2+\dfrac{6}{7}x\)

=> \(\dfrac{6}{7}x-\dfrac{6}{7}x=2+\dfrac{2}{7}\)

=> \(0=\dfrac{16}{7}\)

Vậy pt vô nghiệm

c) x(x - 1) = (x - 2)(x + 2)

=> x² - x = x² + 2x - 2x - 4

=> -x - 2x + 2x = -4

=> -x = -4

=> x = 4

Vậy............

d) \(\dfrac{5x-2}{3}=\dfrac{5-3x}{2}\)

=>\(\dfrac{2\left(5x-2\right)}{6}=\dfrac{3\left(5-3x\right)}{6}\)

=> 10x - 4 = 15 - 9x

=> 10x + 9x = 15 + 4

=> 19x = 19

=> x = 1

Vậy..............