{{4/5,-1/5,-4/5},{3/5,-2/5,2/5},{-2/5,-2/5,7/5}} * {{1,1,3},{-1,0,3},{0,1,1}}

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.