Plot3D[1+x+y+(x+y)^2 +(x+y)^3 +(x+y)^4, {x, -0.5, 0.5}, {y, -0.5, 0.5}]

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.