HP50G Launch Solve equation app in a program

[MNH]

Try calling the built-in menu for the solve equation app from within your program.

To specify a particular page of a menu, enter the number as m.pp, where m is the menu number and pp is the page number (such as 94.02 for page 2 of the TIME menu). If page pp doesn’t exist, page 1 is displayed (94 gives page 1 of
the TIME menu).

HP 50g Advanced User's Reference Manual Edition 2
http://www.hpcalc.org/search.php?query=hp+50g+aur

See The Menu-Number Table H-1 through H-5, pages 637 through 641.