I opened your file, made a recalculation of the worksheet ("Ctrl + F9") and everything works fine:
dongchi 420 wrote:
...Why Ctrl +F9 ?
I don't kown Ctrl +F9 ??
Because this keyboard shortcut ("Ctrl + F9" - "Calculate Worksheet") came into Mathcad Prime 2.0 from the regular version of Mathcad: