I wish I could follow you
Nice to come across this though
Since 3 x 3 = 9, 9 is divisible by 3. So, 3 would be a factor of any number divisible by 9
3(x^2 -x) -x
6x^2 -3x-x
6x^2 - 4x
we can simplify it more by take 2x as comman factor
so , 2x ( 3x -2 )