You can put this solution on YOUR website! Are you sure this is a quadratic equation?
x + 3 + 2x = x + 3
In order to call it a quadratic equation it must have an "x^2"
The solution to the equation you've given me is:
x + 3 + 2x = x+ 3
3x + 3 = x + 3
2x = 0
x= 0