�ã2x -4 = �ã7x + 9
Don't' have a clue. I tried squaring both sides to get rid of the square root but it just isn't working.
If you mean
√(2x-4) = √(7x+9)
then it's easy. Squaring both sides gets rid of the roots, and you have
2x-4 = 7x+9
5x = -13
x = -13/5
But, then 2x-4 < 0 and √(2x-4) is undefined.
So, since you say that "isn't working" I assume you meant
√(2x-4) = √7x + 9
In that case, things do get a bit trickier, because you have to square things twice.
√(2x-4) - √(7x) = 9
(2x-4) - 2√((2x-4)(7x)) + (7x) = 81
9x-4 - 2√(14x^2-28) = 81
2√(14x^2-28) = 9x-85
Now square again
4(14x^2-28x) = 81x^2 - 1530x + 7225
25x^2 - 1418x + 7225 = 0
and that's just a good old quadratic equation.
Still, things get messy. What did you try? Copy/paste the √(2x-4) = √7x + 9 symbol from here, as your font mangled (at least for me).