First of all you always solve the brackets first, to do this you need to multiply each item in the bracket by what is beside it:
3(3x - 1) = 9x - 3
2(3 - x) = 6 - 2x
And place it back in to the equation:
9x - 3 + 6 - 2x = 0
You can then solve the non x numbers:
-3 + 6 = 6 - 3 = 3
And place it back in to the equation...
9x + 3 - 2x = 0
Like we did for the -3 and 6, you need to solve the X's:
9x - 2x = 7x
And place it back in to the equation...
7x + 3 = 0
Then you minus 3 from both sides so you move it over to the right hand side:
7x + 3 - 3 = 0 - 3
Then solve it...
7x = -3
Then you divide both sides by 7 to get 1 X:
7x / 7 = -3/7
x = -3/7 (you can keep it as a fraction)
The answer is X = -3/7,
Hope this helps! :)