Apply suggestions from code review

No need to retain unused old code.

Author: drdrew42

OpenProblemLibrary/FortLewis/DiffEq/2-Higher-order/06-Forcing-resonance/KJ-3-10-07.pg

@@ -59,11 +59,6 @@ $w = 8;
 
 $F = Formula("2*$a cos($w t)")->reduce();
 
-## this does too much rounding for some seeds
-#$c1 = Compute("3*$a/200");
-#$c2 = Compute("(2*$c1-8*$a/50)/6");
-#$c3 = Compute("-3*$a/200");
-#$c4 = Compute("$a/50");
 $c1 = Formula("3*$a/200");
 $c2 = Formula("-13*$a/600");
 $c3 = Formula("-3*$a/200");

OpenProblemLibrary/FortLewis/DiffEq/2-Higher-order/06-Forcing-resonance/KJ-3-10-08.pg

@@ -59,10 +59,6 @@ $w = 8;
 
 $F = Formula("$a e^(-t)")->reduce();
 
-## this does too much rounding for some seeds
-#$c1 = Compute("-$a/74");
-#$c2 = Compute("($a/74 + 2*$c1)/6");
-#$c3 = Compute("$a/74");
 $c1 = Formula("-$a/74");
 $c2 = Formula("-$a/444");
 $c3 = Formula("$a/74");

OpenProblemLibrary/FortLewis/DiffEq/2-Higher-order/06-Forcing-resonance/KJ-3-10-09.pg

@@ -60,11 +60,6 @@ $w = 6;
 
 $F = Formula("$a sin($w t)")->reduce();
 
-## this does too much rounding for some seeds
-#$c1 = Compute("6*$a/296");
-#$c2 = Compute("(2*$c1 - 6*$a/296)/6");
-#$c3 = Compute("-6*$a/296");
-#$c4 = Compute("$a/296");
 $c1 = Formula("3*$a/148");
 $c2 = Formula("$a/296");
 $c3 = Formula("-3*$a/148");