View of /trunk/NationalProblemLibrary/ASU-topics/set119LinearSystems/p16.pg

    1 ## DESCRIPTION
    2 ## Systems of Linear Equations
    3 ## ENDDESCRIPTION
    4 
    5 ## KEYWORDS('Algebra' 'Linear Equations')
    6 ## Tagged by tda2d
    7 
    8 ## DBsubject('Algebra')
    9 ## DBchapter('Systems of Equations and Inequalities')
   10 ## DBsection('Systems of Linear Equations')
   11 ## Date('')
   12 ## Author('')
   13 ## Institution('ASU')
   14 ## TitleText1('')
   15 ## EditionText1('')
   16 ## AuthorText1('')
   17 ## Section1('')
   18 ## Problem1('')
   19 
   20 DOCUMENT();        # This should be the first executable line in the problem.
   21 
   22 loadMacros(
   23 "PG.pl",
   24 "PGbasicmacros.pl",
   25 "PGchoicemacros.pl",
   26 "PGanswermacros.pl",
   27 "PGauxiliaryFunctions.pl",
   28 "PGasu.pl",
   29 "extraAnswerEvaluators.pl"
   30 );
   31 TEXT(beginproblem());
   32 $showPartialCorrectAnswers = 1;
   33 
   34 $x=random(-3,3,1);
   35 $y=random(-3,3,1);
   36 $b1 = -$x + $y ;
   37 $b2 = 4*$x - 3*$y;
   38 
   39 BEGIN_TEXT
   40 Use the substitution method to solve the system
   41 \[
   42 \begin{array}{l}
   43         -x+y = $b1, \\
   44         4x-3y = $b2. \\
   45 \end{array}
   46 \]
   47 $BR
   48 Your answer is: \{ans_rule(25) \}
   49 $BR
   50 If there is more than one point, type the points separated by a
   51 comma (i.e.: (1,2),(3,4)).
   52 If the system has no solution, type
   53 $BITALIC none $EITALIC in the answer blank.
   54 END_TEXT
   55 
   56 $ans1 = $x;
   57 $ans2 = $y;
   58 
   59 #ANS(num_cmp($ans1));
   60 #ANS(num_cmp($ans2));
   61 ANS(interval_cmp("($ans1, $ans2)", strings=>["none"],unions=>'no'));
   62 
   63 ENDDOCUMENT();        # This should be the last executable line in the problem.