Discriminant Solutions Calculation Batch File (Square Root) (Follow up) - batch-file

Question

I am trying to create a program that has the user input 3 values which the program then proceeds and uses as the A, B and C respectively in the ax^2+bx+c (discriminant = D) and gives you the "solutions" it has (if D>0 then 2 solutions, if D = 0 one "double" solution and if D < 0 it will display that there are no real solutions).
#echo off
setlocal enabledelayedexpansion
:arxh
cls
echo *****************************************
echo *Theleis na trekseis to programma (Y/N)?*
echo *****************************************
set /p V=
if /I %V%==Y goto start
if /I %V%==N goto end
echo ~~~~~~~~~~~~~~~~~~~~~~~~~
echo ~Kane thn swsth epilogh!~
echo ~~~~~~~~~~~~~~~~~~~~~~~~~
pause
goto arxh
:start
echo --------------------
echo Dwse mou thn timh A:
echo --------------------
set /p A=
echo --------------------
echo Dwse mou thn timh B:
echo --------------------
set /p B=
echo --------------------
echo Dwse mou thn timh C:
echo --------------------
set /p C=
goto calculation
:calculation
set /a D=%B%*%B%-4*%A%*%C%
echo **************************************************************************
echo ----------------------
echo Timh diakrinousas: %D%
echo ----------------------
if %D% LSS 0 goto error
if %D% GTR 0 goto positive
if %D%==0 goto zero
:error
echo ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
echo ~Arnhtikh timh diakrinousas! Den uparxoun pragmatikes luseis!~
echo ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pause
goto arxh
:positive
setlocal enabledelayedexpansion
set count=0
set /p dend=Vale edw thn timh ths diakrinousas:
set num=%dend%
for /l %%i in (%dend%, -1, 1) do (
set /a sqr=%%i*%%i
if !sqr! leq %dend% (
set digit=%%i.
set root=%%i
goto out
)
)
:out
call set /a count+=1
if %count% GTR 5 goto next
set /a dend=(%dend%-%sqr%)*100
set /a div=%root%*2
for /l %%i in (9,-1,0) do (
set /a sqr=%div%%%i*%%i
if !sqr! leq %dend% (
set root=%root%%%i
goto out
)
)
:next
set root=%root:~-5%
if %dend% neq 0 set digit=%digit%%root%
goto results
:results
set /p S=%digit%
set /a Q=(-%B%+%S%)/2*%A%
set /a R=(-%B%-%S%)/2*%A%
echo ----------------------------------------------------
echo H prwth riza einai ~%Q%~ kai h deuterh einai ~%R%~ !
echo ----------------------------------------------------
echo *****************Approximate Value*******************
pause
goto arxh
:zero
set /a Z=-b/2*A
echo -------------------------
echo H diplh riza einai: %Z% !
echo -------------------------
pause
goto arxh
:end
end
I found a program that the user inputs a number and it finds the square root of said number! I converted the code, so that the user would not input that number, but instead the number would be the discriminant (the number A,B and C would make in the equation).
No matter how hard i try, I get missing operants errors or unbalanced parenthesis or it displays to me the root of the discriminant but doesn't proceed to use it correctly in the equations below. Seriously I am stuck.
Some help would be appreciated!
P.S. don't run the code snippet, I am new here, so I used that tool to display the code.
Thank you in any case