You can put this solution on YOUR website! Okay, I am assuming that by x2 you mean x times 2, so I will just write it 2x.
2x - 6x + 18 = 0 (given)
-4x + 18 = 0 (combine like terms)
-4x = -18 (subtract 18 from both sides)
x = 9/2 (divide by -4 to solve for x)