0
If: 12 = 9x+3
Then: 12-3 = 9x
And: 9 = 9x
So: x =1
If: 9x = 21x-3
Then: x = 1/4 or 0.25
9x + 3 - 6x - 2 = 3x + 1
x - 10x = 9x, so 9x + 3 = 0, so 9x = -3 so x = -1/3
3 / 9x+6
3 / 3(3x+2)
1 / 3x+2