solving 2 unknown variables with 2 equations

For a project (designing a log splitter) at school I am now working with Mathcad for the first time. However, I am now running into some problems. Maybe it's something really silly but I can't manage to solve two unknown variables from two equations. On the internet it is done with the find() function, but for me it doesn't work. Each time the 'find' function will output the follow: Find(Ay, By) --> Find(Ay, By) where Ay and By are the unknown values.

If anyone knows how to do this, please let me know.

All variables and other text is in Dutch but this should not be a problem as it only concerns page 3.

thank you in advance!

Dennis,