checkfile=exos/checkfile8.proc
!set n=$counter
image=0
math=0
questiontype=0
!if $level=0
    R=$counter
!else
    R=$level
!endif        

!if $variabelen=1
    letters=a,b,c,d,f,x,y,z,p,g,k,t,r,n,m
    letters=!shuffle $letters 
    var1=!item 1 of $letters
    var2=!item 2 of $letters
    var3=!item 3 of $letters
    var4=!item 4 of $letters
!else
    var1=x
    var2=y
    var3=u
    var4=v
!endif   
getallen=!shuffle 2,3,4,5,6,7,8,9,10
a=!item 1 of $getallen
b=!item 2 of $getallen
c=!item 3 of $getallen
d=!item 4 of $getallen
e=!item 5 of $getallen
f=!item 6 of $getallen
g=!item 7 of $getallen
h=!item 8 of $getallen     	
pm=!randitem +,-
mp=!randitem +,-
mm=!randitem +,-
    
exotitle=!record 65 of lang/remarks.$taal
#@ Schrijf het volgende stelsel van drie vergelijking op als &eacute;&eacute;n vergelijking 
question$n=!record 66 of lang/remarks.$taal
#@ Schrijf de drie vergelijkingen als &eacute;&eacute;n formule <br><em>Geef <tt>$var2</tt> als functie van <tt>$var1</tt></em>.

!if $R=1
    # k=x mm d
    # z=k*x pm b => z=(x mm d)*x pm b
    # y=z mp  c
    # texanswer$n= y=(x mm d)*x pm b mp c 
    g=!exec pari A=($var1 $mm $d)*$var1 $pm $b $mp $c \
    printtex(A)
    g1=!line 1 of $g
    g2=!line 2 of $g
    texanswer$n=$var2 \,=\, $g2
    answer$n=$g1
    formula$n=\left\{ \begin{array}{l}$var4=$var1 $mm $d \\ $var3 = $var4 \cdot $var1 $pm $b \\ $var2 = $var3 $mp $c \end{array}\right.
 !exit
!endif
	
!if $R=2
    # k=e*x mm d
    # z=kx pm b => z=x*(e*x mm d) pm d
    # y=dz mp  c
    # texanswer$n= y = d*(x*(e*x mm d) pm d) pm c
    g=!exec pari A=$d*($var1*($e*$var1 $mm $d) $pm $d) $pm $c\
    printtex(A)
    g1=!line 1 of $g
    g2=!line 2 of $g    
    texanswer$n=$var2 \,=\, $g2
    answer$n=$g1
    formula$n=\left\{ \begin{array}{l}$var4=$e \cdot $var1 $mm $d \\  $var3 = $var4 \cdot $var1 $pm $b \\ $var2 = $d \cdot $var3 $mp $c \end{array}\right.
 !exit
!endif
	
!if $R>2
    # k=x/e mm d
    # z=kx pm b => z=x*(x/e mm d) pm d
    # y=dz mp  c
    # texanswer$n= y = d*(x*(x/e mm d) pm d) pm c
    g=!exec pari A=$d*($var1*($var1/$e $mm $d) $pm $d) $pm $c\
    printtex(A)
    g1=!line 1 of $g
    g2=!line 2 of $g    
    texanswer$n=$var2 \,=\, $g2
    answer$n=$g1
    formula$n=\left\{ \begin{array}{l}$var4=\frac{1}{$e} \cdot $var1 $mm $d \\  $var3 = $var4 \cdot $var1 $pm $b \\ $var2 = $d \cdot $var3 $mp $c \end{array}\right.
 !exit
!endif
	
