one unknown solving( simple)

[szatynkabuduje]

what is this?? could anybody tell me? i just want the simple answer..

[-MFra-]

Hi Lina,

[szatynkabuduje]

Thank you so much !!!!

[ValeryOchkov · Accepted solution]

[Fred_Kohlhepp]

Try

I think (I can't really read your picture too well) that you need meter squared in your constraint.  But that poses another issue--Mathcad symbolics doesn't handle units well