Hi,
Daniel is quite right: a clear description of the problem would help. You say:
solve an equation containing a combination of 'x' square, 'x' and
under root 'x' along with other coefficients
This following equation has
$x^2$,
$x$ and
$\sqrt{x}$ with a couple of coefficients and solves just fine:
NSolve[2 x^2 - x + 3 Sqrt[3 x] - 2 == 0, x]
(*{{x -> -0.847034 + 1.29585 I}, {x -> -0.847034 - 1.29585 I}, {x -> 0.164977}}*)
Even for the general form you get an analytical solution if you want:
Solve[a x^2 + b x + c Sqrt[d x] - 2 == 0, x]
Here is the first of the solution Solve finds:
So these guys are a bit long.
Solve[a x^2 + b x + c Sqrt[d x + e] + g == 0, x]
evaluates in about 4/100 of a second on my machine. So without further specification of the problem it will be difficult to help.
Best wishes,
Marco