I have a problem with this code. It does not simplify the fraction and does not multiply radicals. Advice please
Context("Numeric");
Context()->strings->add(none=>{},EmptySet=>{alias=>"none"});
$a = random(2,8,1);
$b = random(2,5,1);
$c = random(2,7,1);
$d = random(3,11,2);
$ans = Compute("(($a-sqrt($d))*($b+sqrt($c)))/($b^2-$c)");;
########################################################################
Context()->texStrings;
BEGIN_TEXT
Simplify
\[
\frac{$a-\sqrt($d)}{$b-\sqrt{$c}}.
\]
$PAR
\{ ans_rule(30) \}
END_TEXT
Context()->normalStrings;
ANS( $ans->cmp() );
ENDDOCUMENT()