This question is out of context. I'm going to assume you're using this equation template:
ax^2 + bx + c = 0
If so, get the equation into that form
-2x = -3x^2 + 11
Typically, they'll want the leading term to be positive
To do this, add 3x^2 to each side and subtract 11 from each side to get this
3x^2 - 2x - 11 = 0
Therefore,
a = 3
b = -2
c = -11