Plot3D not showing any image

Questions
1

I have just started using Mathematica. I am trying to plot3D a function but the output is not being displayed by mathematica after entering the basic commands. I would kindly appreciate any assistance.

Plot3D[(-\[Beta]\[Gamma] + 
Sqrt[\[Beta]^2  (1 + \[Beta])  (\[Beta]\[Gamma] + \[Gamma]^2)])/(\
\[Beta]^2 \[Gamma]), {\[Beta], 0.2, 2.5}, {\[Gamma], -10, 10}]
2

Plot3D[(-[Beta][Gamma]+Sqrt[[Beta]^2(1+[Beta])([Beta][Gamma]+[Gamma]^2)])/
([Beta]^2*[Gamma]),{[Beta],0.2,2.5},{[Gamma],-10,10}]

3

It worked. Thank you so much!