In an equation with fractions, we can get rid of the denominators by multiplying each term by the LCD (LCM of denominators).
IN this case the LCM is color(red)(3(x-1)(x+1))3(x−1)(x+1)
(color(red)(3(cancel(x-1))(x+1))xx2)/cancel(x-1) - (color(red)(cancel3(x-1)(x+1))xx2)/cancel3 =(color(red)(3(x-1)cancel(x+1))xx4)/(cancel(x+1)
After cancelling the denominators, this leads to a simpler equation.
6(x+1) -2color(blue)((x-1)(x+1))=12(x-1)" "color(blue)(DOTS)
6x+6 -2(x^2-1) = 12x-12
6x+6 -2x^2+2=12x-12" make =0"
0 = 2x^2+6x-20" "div 2
x^2+3x-10= 0" factorise"
(x+5)(x-2)= 0
x = -5 or x = 2