(* Make a 3D plot of the gravitational potential due to two point masses of mass 1 and mass 4, located at (-2,-2) and (2,2), respectively. *)

Plot3D[(1/Sqrt[(x+2)^2+(y+2)^2])+(4/Sqrt[(x-2)^2+(y-2)^2]),
{x,-5,5},{y,-5,5},
AxesLabel -> {"x (m)","y (m)","V"},
PlotRange->{0,7.5},PlotPoints->50,Ticks->{Automatic, Automatic, Automatic}]

(* Make a 2D contour plot of the gravitational potential due to two point masses of mass 1 and mass 4, located at (-2,-2) and (2,2), respectively. *)
ContourPlot[(1/Sqrt[(x+2)^2+(y+2)^2])+(4/Sqrt[(x-2)^2+(y-2)^2]),{x,-5,5},{y,-5,5},FrameLabel->{"x (m)","y (m)"}, ContourLabels->True]