{{1/8,0,-1},{1,-1/24,1/20},{1/15,1,1/60}} {{39/40,0,0},{0,93/100,0},{0,0,87/100}} inverse({{1/8,0,-1},{1,-1/24,1/20},{1/15,1,1/60}} )

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.