!set n=$counter
!if $level =0
    R=$counter
!else
    R=$level
!endif    


!if $subject=9
    breuken=0
    steps=0
    variabelen=0
!endif

!if $variabelen=1
    var1=!randitem a,b,c,d,f,x,y,z,p,g,k,t,r,n,m
!else
    var1=x
!endif
varlist=$var1
mathviewpanel=$module_title:->:/:*:-:+
question$n=!record 30 of lang/remarks.$taal
#@ Los de volgende vergelijking op <br>(Bereken dus de waarde van de letter)
!if $steps=1
    math=0
    checkfile=exos/checkfile4.proc
    tekst=!record 31 of lang/remarks.$taal
    #@En laat ook een paar tussenstappen zien...
    question$n=$(question$n)<br>$tekst
    var5=6
    var4=2
!else
    var5=1
    var4=1
    math=1
    checkfile=exos/checkfile1.proc
!endif

gg=!randint 2,25
pm=!randitem -1,1
answer$n=$[$pm*$gg]

!if $breuken=1
    a=!randitem 1/2,1/3,1/4,1/5,1/6,1/7,1/8,1/9,1/10,2/3,3/4,2/5,3/5,5/6,2/7,3/7,4/7,5/7,6/7,3/8,5/8,7/8,2/9,5/9,7/9,8/9,3/10,7/10,9/10	
    aa=!replace internal / by , in $a
    a1=!item 1 of $aa
    a2=!item 2 of $aa
    b=!randint 2,25
    !if $R=1 	
	#ax+b=c
	cc=!exec pari A=$a*$(answer$n) + $b\
	printtex(A)
	c=!line 1 of $cc
	C=!line 2 of $cc
	formula$n=\frac{$a1}{$a2} \cdot $var1 + $b = $C 
	texanswer$n=$var1 = \frac{$a2}{$a1} \cdot \left($C - $b\right) \Longrightarrow $var1 = \frac{$[$a2*($c - $b)]}{$a1} = $(answer$n)
     !exit
    !endif
    
    !if $R=2 
	#ax-b=c
	cc=!exec pari A=$a*$(answer$n) - $b\
	printtex(A)
	c=!line 1 of $cc
	C=!line 2 of $cc
	formula$n=\frac{$a1}{$a2} \cdot $var1 - $b = $C 
	texanswer$n=$var1=\frac{$a2}{$a1} \cdot \left($C + $b\right) \Longrightarrow $var1 = \frac{$[$a2*($c + $b)]}{$a1} = $(answer$n)
     !exit
    !endif
	
    !if $R=3 
	#ax + bx = c
	cc=!exec pari A=$(answer$n)*($a + $b)\
	printtex(A)
	c=!line 1 of $cc
	C=!line 2 of $cc    
	formula$n=\frac{$a1}{$a2}\cdot $var1 + $b\cdot $var1 \,\,\,=\,\,\, $C 
	texanswer$n=\frac{$[$a2*$b + $a1]}{$a2} \cdot $var1\,\,=\,\, $C \Longrightarrow $var1  =\frac{$a2}{$[$a2*$b + $a1]}\cdot $C = $(answer$n)
     !exit
    !endif
	
    !if $R>3 
	#ax - bx = c
	cc=!exec pari A=$(answer$n)*($a - $b)\
	printtex(A)
	c=!line 1 of $cc
	C=!line 2 of $cc    
	formula$n=\frac{$a1}{$a2}\cdot $var1 - $b\cdot $var1 \,\,\,=\,\,\, $C
	texanswer$n=\frac{$[$a1 - $a2*$b]}{$a2} \cdot $var1\,\,=\,\, $C \Longrightarrow $var1  =\frac{$a2}{$[$a1-$a2*$b]}\cdot $C = $(answer$n)
     !exit
    !endif
!else
    a=!randitem 2,3,4,5,6
    b=!randitem 2,3,4,5,6
        
    !if $R=1 
	#ax+b=c
	c=$[$a*$(answer$n) + $b]	    
	formula$n=$a\cdot $var1 + $b \,\,\,=\,\,\, $c 
	texanswer$n=$a\cdot $var1 = $c - $b \Longrightarrow $var1 = \frac{$[$c - $b]}{$a} = $(answer$n)
     !exit
    !endif
    !if $R=2 
	#ax-b=c
	c=$[$a*$(answer$n) - $b]	    
	formula$n=$a\cdot $var1 - $b \,\,\,=\,\,\, $c 
	texanswer$n=$a\cdot $var1 = $c + $b \Longrightarrow $var1 = \frac{$[$c + $b]}{$a} = $(answer$n)
     !exit
    !endif
    !if $R=3 
	#ax + bx = c
	c=$[$(answer$n)*($a+$b)]
	formula$n=$a\cdot $var1 + $b\cdot $var1 \,\,\,=\,\,\, $c 
	texanswer$n=$[$a + $b] \cdot $var1\,\,=\,\, $c \Longrightarrow $var1 \,\,=\,\, \frac{$c}{$[$a + $b]} = $(answer$n)
     !exit
    !endif
    !if $R>3 
	#ax - bx = c
	a=!randitem 7,8,9,10
	b=!randitem 2,3,4,5
	c=$[$(answer$n)*($a-$b)]
	formula$n=$a\cdot $var1 - $b\cdot $var1 \,\,\,=\,\,\, $c 
	texanswer$n=$[$a - $b] \cdot $var1\,\,=\,\, $c \Longrightarrow $var1 \,\,=\,\, \frac{$c}{$[$a - $b]} = $(answer$n)
     !exit
    !endif
 !exit
!endif

