Unable to Factor error on HP 50g graphing calculator , why it occur ?!

[JKova]

Hi dear HP Community , 

I have one question for you. So before couple of months I was solving one of my programs and I used SOLVE function which was built in in HP 50g graphing calculator. Also i write a code which is similar to this in the picture(s). Program is really large. Program execution starts very well but in some point i get this ERROR -- Unable to Factor at the top of my screen. 

Also i realized that SOLVE function is very slow , or is it because of my program. 

Program code is listed below.

before code you need to know which are the input variables and variables which you search as solution to the task , and also all formulas ( equations ) which is visible to you as user.

Variable which you search for ( in terms of numerical result ) - "ULAZ1" , known variables by values - "ULAZ2" and equations together with their definitions { { 'equation i' { 1st place in list - variable which you search for as result of using equation , 2nd place - second variable , ... , n -th place - nth variable in equation } } - "formulas"

And below is one smaller program ...

source code for "smaller program"

and below is also source code for bigger program which simple goes from smaller program. I draw a red rectangle over names of program in the picture of source code at smaller program which includes also a bigger program too "PRS522"

source code for bigger program ... included red rectangles in the name of program and on every spot in which SOLVE funciton exist ... there's nothing wrong with this program so far

So , my question after all of these would be - why should this error occur ... also program work fine on my emulator for HP 50g graphing calculator ( I'm thinking of HP User Edit 6 ) and don't know reason why is this happening.

Also I'll share with you a video link about this topic. In video I calculate the area of triangle when i had known values of a and b , a were 3 , b were 4 if ... also watch a video if I'm not correct with this 😀

Thanks for any helpful explanation or tricks&tips , 

bye 🤗